[accrual]

I loved the K-Lite Codec Pack and CCCP (Combined Community Codec Pack) back in the XP days, especially while exploring MKVs and anime, but I virtually never run into a media file that VLC or MPC-HC can't play by default these days. Just drop it in and it plays.

[notpushkin]

If I understand correctly, most of what K-Lite / CCCP did was wrapping libavcodec/libavformat for the Windows APIs, so native players could use them. VLC just ships with libavcodec included, so it supports all these formats. Not sure about MPC-HC nowadays (it used to use Windows APIs, but you’d usually get it with your codec pack installer anyway).