Uh-oh ... you said "codec pack". Those are one of the worst things you could put on a computer. Once upon a time, you needed a lot of system codecs to play videos, but we outgrew that some years ago. Software like VLC now has internal codecs to playback video. The only system-wide codecs you need are for editing (to read the source files).
Codec packs are poorly written, usually made by (and used, and popular with!) illegal downloaders of movies. Very often, the codecs conflict, and can entirely destroy a computer.
I've seen some bad codecs packs -- K-lite being the most infamous of them -- do so much damage that the computer had to be re-formatted and Windows re-installed. It just made a huge mess of things.
If you can uninstall that thing, do so.
Only add codecs you need, one by one. XVID is a good one to have, as well as lossless codecs like HuffYUV and HuffYUV-MT (multi-threaded).
The spelling-Nazi in me is so happy to see somebody use "voila" correctly -- so tired of seeing "walla" or some silly similar spelling.
