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View full siteThis document explains the purpose of all the files used by Opera 6 for Windows. This can be useful for everyone who likes to tinker with their copy of Opera, for those who manually make separate profiles for different uses or users, or for those who have tinkered and would like to know how to survive a new installation process.
Warning: tinkering can make your copy of Opera unusable, or cause data loss. Always make backups before making any changes.
This information is valid for installations of Opera 6 for Windows. Files with the number '6' in their name were also present in earlier Opera versions, but with a lower number or no number in their filename.
Directories
Main Opera directory | acpo | Buttons | Cache4 | Classes | Help | Images | Mail | Program | Skin | Styles | UnInst
Main Opera directory
Program modules | Stored usage data | Saved user data | Various other files
| Filename | Use | Format | Overwritten on install | Tweak info [1] |
|---|---|---|---|---|
| chartables.bin | Contains tables for Unicode support | binary | yes | - |
| es262-32.dll | ECMAScript (JavaScript) module. | binary | yes | - |
| OMail32.dll | Mailer module (also responsible for posting newsgroup articles). | binary | yes | Removable. This has the same effect as disabling the e-mail client from "File > Preferences > Programs and paths". |
| Opera.exe | Main program executable. | binary | yes | - |
| Opjpeg32.dll | Jpeg module. | binary | yes | - |
| Oppng32.dll | PNG module. | binary | yes | - |
| OpTree32.dll | Tree module, used in the Hotlist for bookmarks, contacts and mail. | binary | yes | - |
| OpUniAnsi.dll | Unicode to Ansi conversion | binary | yes | - |
| xmlparse.dll | XML parser module. | binary | yes | - |
| zip.dll | Zip module. | binary | yes | - |
| Filename | Use | Format | Overwritten on install | Tweak info [1] |
|---|---|---|---|---|
| autopera.win | Stores a snapshot of the currently opened windows in 'Saved windows' format. This file is used when you select the startup option "Continue browsing where I was last time". After a crash of the browser, this is the default option on the recovery menu. | binary | no | - |
| button.dat | Stores the dropdown list of button.ini file addresses for toolbar button sets. Each time you select a new file it will be added to the list. | text/plain | no | - |
| cookies4.dat | Stores cookies. | binary (see description) | no | File is removable, but to delete all cookies at once, you can also
use 'Delete private data' from the File menu in Opera. Editable with Joe Segur's Opera File Explorer, a third party helper app. |
| download.dat | Stores information about recent downloads, as seen in the Transfer window. Useful to keep track of downloaded files and enable the 'Resume download' function. | binary | no | File is removable, but to delete all download data, you can also use
'Delete private data' from the File menu in Opera. There's an opera.ini-only setting for the number of days to keep download data available: LogEntryDaysToLive= under [User Prefs]. |
| global.dat | Stores the global history. Properties for the Global history are set from "File > Preferences > History and cache". URLs stored in the Global history are used for the auto complete function, and can be checked from "Window > Special > History". | text/plain | no | File is removable, but to clear the global history, you can also use
'Delete private data' from the File menu in Opera. Easy to edit with Joe Segur's Opera File Explorer, a third party helper app. |
| jswarn.dir | Stores sites which don't need the warning about a Javascript reading password fields (new in 6.02). | text/plain | no | - |
| news.rc | Index of news000x.rc files. | binary | no | - |
| news000x.rc | Index of newsgroups for each visited newsgroup server. | binary | no | - |
| opcacrt6.dat | Stores CA Certificates | binary | no | More info about certificates. |
| opcert6.dat | Stores Personal Certificates and private keys | binary | no | More info about certificates. |
| opera.dir | Stores 'Go to page' dialog history. This can be accessed from the Go To dialog, and clicking on the arrow to the right of the input field. | text/plain | no | File is removable, but to clear the 'Go To' dialog history, you can also use 'Delete private data' from the File menu in Opera. |
| oprand.dat | Random seed file, used for generating keys | binary | no | - |
| opssl6.dat | Stores SSL preferences | binary | no | - |
| OUsr600.dat | Stores registration information | binary | no | Can be removed to de-register your copy of Opera. |
| urlwarn.dir | Stores sites which don't need the warning about an URL possible disguised with user/password info (new in 6.02). | text/plain | no | - |
| viewers.dat | (Opera 5 only) Saved preferences for handling downloads. Not used anymore in Opera 6. | binary | no | - |
| vlink4.dat | Stores visited links. | binary | no | File is removable, but to clear all visited links at once, you can
also use 'Delete private data' from the File menu in Opera. Editable with Joe Segur's Opera File Explorer, a third party helper app. |
| Filename | Use | Format | Overwritten on install | Tweak info [1] |
|---|---|---|---|---|
| adprefs.ini | Stores advertising prefs, as entered by the user. Only used with unregistered copies. See also our privacy policy. | text/plain | no | Editable, but settings can be changed more easily in the browser. |
| im.ini | Stores info about IM account(s). | text/plain | no | Editable, but settings can be changed more easily in the browser. |
| Contacts.adr | Stores contacts used for e-mail and instant messaging. | text/plain | no | File can be saved and renamed, and another file can be selected. See
the local menu on the Contacts tab in the Hotlist window. Editable, but can be changed more easily in the browser. |
| Opera6.adr | Stores bookmarks. | text/plain | no [2] | File can be saved and renamed, and another file can be selected. See
the local menu on the Bookmarks tab in the Hotlist window. Editable, but can be changed more easily in the browser. Several third party bookmark managers provide an export function. |
| Opera6.ini | Stores program settings. | text/plain | Warning! Read note carefully! [3] | The ini file to be used can be specified on the command line and with
the Opera shortcut link. This way you can make multiple shortcuts, which
start Opera with different settings. If this file is removed, a new opera6.ini will be created by Opera on the next run, containing some basic settings. Editable only when Opera is not running. Some settings can be changed more easily in the browser, others can only be changed editing this file. See our list of opera.ini entries. |
| Opera.win | Saved windows settings. | binary | no | File can be saved ("Window > Save window setup..."), and another
file can be selected ("File > Preferences > Start and Exit"). Removing this file will cause an error message if Opera is set to start with 'Show saved windows setup'. |
| Filename | Use | Format | Overwritten on install | Tweak info [1] |
|---|---|---|---|---|
| License.txt | Contains the license governing the use of the Software | text/plain | yes | - |
| lngcode.txt | Contains a list of languages and their two letter code. This is used in Opera when choosing preferred languages for web pages ("File > Preferences > Languages"). | text/plain | yes | - |
| Opera.ocv | Contains customization info, used on installing Opera to enter the relevant lines into "Opera.ini". Only included in customized versions. | text/plain | yes | - |
| plugin-ignore.ini | Stores a list of plugins that Opera will ignore because they cause serious problems for Opera. | text/plain | yes | - |
| Readme.txt | System requirements and information on installing Opera | text/plain | yes | - |
| search.ini | Stores settings for the search engines used in Opera. This file is not in all localized versions present (new in 6.01). | text/plain | yes | - |
| *.lng | Language file, translates all strings in Opera's User Interface. Included in localized versions, but not part of the standard English version. | text/plain | yes, when installing the same language | Separate language files (including a file containing the default English strings) can be downloaded from the download section of Opera's website. Edit strings whenever you like. Choose your edited file from "File > Preferences > Languages". If you remove lines from the language file, the default (English) strings of Opera will be used for the missing strings. |
acpo
| Filename | Use | Format | Overwritten on install | Tweak info [1] |
|---|---|---|---|---|
| acpoxxxxxx.bin | These files contain info about the ads shown in the ad window. See www.opera.com/docs/ads/ for a detailed explanation. | binary | no | - |
Buttons
The two folders 'Standard' and 'Classic' contain images and settings for two button sets. Choosing between the button sets is done from "File > Preferences > Browser look".
| Filename | Use | Format | Overwritten on install | Tweak info [1] |
|---|---|---|---|---|
| *.png and *.gif | See the Composer tutorial for a list of the buttons used for 5.12. For Opera 6, more images have been added. All images used in Opera can now be skinned. | image/png (image/jpeg, image/gif or image/x-windows-bmp are also possible for button files) |
yes | The format of the buttons.ini file for the 'Standard'
button set should be self-explanatory. Knowledge Base article 422 and Knowledge Base article 518 contain tips but are not updated for Opera 6. See http://my.opera.com/customize/ for a collection of button sets. |
| buttons.ini | Contains all the settings for a button set. | text/plain | ||
| ReadMe.txt | This file warns you to save edited files somewhere else or under a different name, as the two default button sets *will* be overwritten on a new install. Please pay attention! | text/plain |
Cache4
| Filename | Use | Format | Overwritten on install | Tweak info [1] |
|---|---|---|---|---|
| dcache4.url | Index of the cached files; without index the files are useless. dcache4.url is updated on closing Opera. | binary | no | Cache settings can be found at "File > Preferences
> History and Cache". These files are removable, but to empty the cache, you can also use 'Delete private data' from the File menu in Opera. Editable with Joe Segur's Opera File Explorer, a third party helper app. |
| oprxxxxx.xxx | These are the cached files. | Same as the original files | no |
Classes
| Filename | Use | Format | Overwritten on install | Tweak info [1] |
|---|---|---|---|---|
| lc.jar | LiveConnect Java code with fewer privileges than opera.jar (new in 6.02) | binary | yes | - |
| Opera.jar | Connection to the Java Runtime Engine | binary | yes | - |
| Opera.policy | Sets permissions for Java applets running inside Opera. | text/plain | yes | When moving the main Opera directory after an install, you need to update the pointer to the directory containing opera.jar (see the last line in the policy). |
Help
| Filename | Use | Format | Overwritten on install | Tweak info [1] |
|---|---|---|---|---|
| *.htm | The actual help files in HTML format | text/html | yes | Localized versions store the help files in a subdirectory. |
| help.css | Style sheet for formatting the help files | text/css | yes | Modified versions can be found at http://www.opera.com/support/resources/. |
| reg_form.txt | Registration form | text/plain | yes | - |
| startup.txt | Contains help for the startup dialog | text/plain | yes | - |
| tipday.txt | Contains the Tip of the Day lines shown on startup. | text/plain | yes | - |
Images
| Filename | Use | Format | Overwritten on install | Tweak info [1] |
|---|---|---|---|---|
| banner.png | Banner to be shown in the ad window on top when Opera is offline. | image/png (image/jpeg, image/gif or image/x-windows-bmp are also possible | yes | - |
| Splash.png | Splash screen, shown on startup. | yes | Disable showing the Splash screen with this opera6.ini settings
under [User Prefs]: Show splash screen=0 |
|
| Startup1.png and Startup2.png | Images for the Startup menu. | yes | - | |
| *.gif | Various images used in Opera when displaying file listings. | image/gif | yes | - |
This directory contains all the mail settings, filters etc. and all the mail boxes, sorted into subdirectories for each account. The location for this directory can be changed in opera6.ini. Other than that reference, the mail system is completely contained in this directory.
| Filename | Use | Format | Overwritten on install | Tweak info [1] |
|---|---|---|---|---|
| *.mbx | The MBX files are standard issue Unix mailbox files, one for each folder. | text/plain | no | - |
| *.idx | The IDX files contain an index for each mailbox. | binary | no | - |
| Account.ini | Stores the account settings, including the password (munged) if you choose so. | text/plain | no | Editable, but settings can be changed more easily in the browser. |
| columns.dat | Saves column widths. One file for each folder. | binary | no | - |
| filters.dat | Stores the filters. One file for each account | text/plain | no | Earlier versions (before 6.0) where language dependent |
| folder.ini | Saves name and other settings. One file for each folder | text/plain | no | - |
| lmos.dat | Keeps track of which messages have been received from the mail server | text/plain | no | If deleted, all mail stored on the mail server will be downloaded again |
Program
| Filename | Use | Format | Overwritten on install | Tweak info [1] |
|---|---|---|---|---|
| Netscape.exe | This is actually a very simple program that starts Opera. Some plugins will only install in the plugins folder when there's a 'Netscape.exe' present in a 'Programs' folder one level up. 'Netscape' is then started again after installing the plugin. | binary | yes | - |
| Plugins\NPSWF32.dll | Shockwave Flash movie player from Macromedia. | binary | yes | More info on plugins |
| Plugins\PlugDef.dll | This is a backup plugin to show when the requested plugin can not be found. | binary | yes |
Skin
This directory contains the default skin 'foreground.png'. The images you choose to use as foreground or background skin (by using the right-mouse-click options for images) will also be stored here. If you select an image more than once, multiple copies will be saved. Images selected from your own system (in the "File > Preferences > Browser look" settings) will not be saved in this directory.
Styles
| Filename | Use | Format | Overwritten on install | Tweak info [1] |
|---|---|---|---|---|
| About.css | Stylesheet for the layout of the About Opera page. | text/css | yes | For tips and tricks regarding customization of Opera's style sheets, and also for getting help in making a nifty User style sheet, visit the newsgroup opera.customize.general. |
| cache.css | Stylesheet for the layout of the Cache page. | text/css | yes | |
| csr.css | Stylesheet for the layout of search results (currently not used in Opera) | text/css | yes | |
| dir.css | Stylesheet for the layout of directory listings. | text/css | yes | |
| drives.css | Stylesheet for the layout of the local drives page. | text/css | yes | |
| history.css | Stylesheet for the layout of the history page. | text/css | yes | |
| im.css | Stylesheet for the layout of Instant Messaging windows | text/css | yes | |
| mime.css | Stylesheet for the layout of e-mail messages and newsgroup articles | text/css | yes | |
| mimehead.css | Stylesheet for the layout of e-mail and newsgroup headers pages. | text/css | yes | |
| opf.css | Stylesheet for the layout of Open E-book Package Files | text/css | yes | |
| plugins.css | Stylesheet for the layout of the plugins page. | text/css | yes | |
| wml.css | Stylesheet for the layout of WML pages (example: WAP Yahoo! UK & Ireland) | text/css | yes | |
| ReadMe.txt | This file warns you to save edited files somewhere else or under a different name, as the default style sheets *will* be overwritten on a new install. Please pay attention! | text/plain | yes | - |
UnInst
| Filename | Use | Format | Overwritten on install | Tweak info [1] |
|---|---|---|---|---|
| DfltBrws\32\*.* | For each file that gets associated with Opera, a file is saved containing the previous 'owner' of the association. This way it is possible to hand back the association to the previous owner. | binary | no, only on changing the default browser settings | Changing associations can be done
|
| Backup\*.* | All files that are replaced during the installation are backed up in this folder. | - | no | If you perform multiple installations in the same directory, duplicate backup files will be saved with numbered file extensions. |
| UNWISE.EXE | Generic WISE uninstall program | binary | yes | - |
| OpUninst.exe | Provides specific helper functions during uninstalling | binary | yes | - |
| OpUninst.ini | Contains data for the Uninstall program | text/plain | yes | - |
| Install.log | Logs all actions (file copied, directories made, registry entries made etc) performed during installation. This file is needed for properly uninstalling Opera | text/plain | no (logs for subsequent installations are appended to this file) | - |
| UnWise.ini | Contains text strings for the Uninstall program | text/plain | yes | - |
Notes
Note [1]
Tweak only while Opera is not running, except when told otherwise. Deleting files will cause data loss! Always make backups before making any changes.
Note [2]
The logic behind the bookmark installation:
- Try to read [User Prefs]Hot List File Ver2 from the opera.ini file
- Do not alter the value if any found
- Default to opera6.adr if no value was found
- Try to install an opera6.adr file, preserve existing if the value from 1 was empty
Opera 5 behaved differently.
Note [3]
Parts of 'Opera.ini' that will be overwritten:
- The [install] section
- The plugin path (if Opera detects a Netscape installation, Netscape's plugins path will be added to Opera's own and other paths already present
- Language file location (if you install a different language version)
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