Ok, so lets get started
What u need:
1. Klite Mega Codec Pack
2. Winamp
Download KLMCP from here:
CODE
http://www.codecguide.com/download_mega.htm
And I assume winamp is already installed, so all u need to do is install all codecs of KLMPC and finish the installation.
Now open winamp and goto options->preferences->plugins->input
Double click "Nullsoft Directshow Decoder"
And add the extension u wanna play e.g., "RA;RM;RMVB;MP4;M4V;MKV;FLV", without("")
Close winamp and start again now try playing the files and u will notice that winamp will pick em up just like any other file it generally plays.
Note: Download "KLMPC" only as "KLCP" does not have real alternative included in the package but if u install KLCP u can still install real alternative seperately.
By default winamp only handles "MPG;MPEG;M2V;AVI" extensions
U can play quicktime files also after installing qt alternative and add the "MOV" to "Nullsoft Directshow Decoder" but protected qt files still require actual qt installed.