If you had problems with it then might be better to leave alone. I just downloded it and ran with setting at default. The problem I had was that WMP 11 decided to not show videos. It would run OK in the preview mode but not if full mode. K-Lite fixed it.
When I downloaded the codec pack I ticked nothing. Under 'tools' in K-Lite in all programs- GSpotv2.70a shows 238 codecs loaded. (Whatever that means!)As ened I downloaded and forgot it. Downloaded from here; click here