when i tried uninstalling k-lite mega codec pack, this error message was displayed:
File "C:\Program Files\K-Lite Codec Pack\unins000.dat" does not exist. Cannot uninstall.
however, the file is there...so wads going on??

Like it says it doesn't exist. Should have a unins000.exe (extension hidden by default) and a unins000.dat in the working directory. Don't know what happened, but other file is missing.

There's an easy solution to this:

1) Install the program again
2) Uninstall the program

Works every time for every program whenever this kind of error comes up