This tutorial is going to teach you how to add custom menu music.
Note that if the bitrate and frequency are right,you can skip directly to step 7 without modifying the MP3 file.
1:Download MP3QualityModifier from here:
http://www.softpedia.com/get/Multimedia/Audio/Other-AUDIO-Tools/MP3-Quality-Modifier.shtml
2:Extract and open the program.
3:Add the desired file (it MUST be of MP3 format)
4:Set the bitrate to 90 (for some clients if it's higher it doesn't work)
5:Set the frequency to 44100 Hz
6:Process
7:Rename the outputed file to gamestartup
8:Copy-paste it in cstrike/media (if the folder media doesn't exist,create it and name it media)







