Ok, try this:
Close all the possible applications and tasks and services in the system, so to minimize the disk access acrivity.
DELETE the file C:\WINNT\SHELLICONCACHE
It is hidden, so you may want to change its attriburtes first, or configure win to show hidden files.
After you did so, wait for a while to make sure there's no (or almost no) activity on disk.
Then reset your pc. You really have to bypass the shutdown procedure because that would recreate the shelliconcache file with the wrong info your pc has in memory. Yes, it really is a brutal reset, so make sure there's no activity on disk. Not a big big problem in NTFS. If you are on FAT than it may be a problem.
Anyway, when your pc reboots the problem should be fixed. Or, at least, you will know that the shelliconcache file is not responsible for the icon change.
If this does not work, then maybe the Icons where really reassigned in the registry, and a poor uninstall procedure did not restore them to their own original applications; in this case you will have to reassign them manually in the registry, which could be painful it the wrong icon assignments are many.
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= Taym =
MK2a #040103216 * 100Gb *All/Colors* Radio * 3.0a11 * Hijack = taympeg