Så fandt jeg noget på nettet, der ligner dit problem (måske).
Her er linket
http://unclean.org/howto/icoicons.html Jeg har også kopieret
Background: I am running Windows 2000 Professional
I was editing and begining to understand .ico files (as in favicon.ico), and I made the mistake of right clicking on one of them, selecting 'Open With', and clicking 'OK' while the "Always use this program to open these files" checkbox was marked. The result was that Windows no longer displayed as icon the actual icons contained in each file. It began displaying a predetermined icon chosen by the program now associated with .ico files. In order to remedy the situation, I performed the following changes:
1. Choose to "always use" Internet Explorer for .ico files (this was done with the right-click described above).
2. Open registry editor (Run -> regedit)
3. As you should do before all registry changes, back it up!
4. Traverse to the following directory in the registry:
hkey_current_user/software/microsoft/windows/currentversion/explorer/fileexts/.ico
5. Delete the key entitled "Application" which contains the data "iexplore.exe"
In case these directions do not work, you might also try deleting all the keys pertaining to programs you've previously used to open .ico files. These keys should be located within the "OpenWithList" directory, which resides in the above-mentioned registry directory. Unfortunately I made both these two changes at once, and therefor did not know whether steps 1-5 are sufficient.