I have like 75 files on step mania and everytime i play a song, it ends up skipping!!
Is it that i just put to much files on it or is it just my computer system?
Some music files (especially MP3 encoding) that has a sampling rate of 48000 kHz or more tends to skip a lot, especially with old sound cards, regardless of their specifications.
Solution: Open your music file in your favorite sound editor, change the sampling rate from <OMGHIGHFREQUENCY> to 44100 kHz. It will solve things.
I get occasional skipping in my StepMania too, and I'm running an Athlon X2 3800+ with 1.75gb PC3200 RAM, a Radeon X800PRO, and an Audigy 2 ZS. The sound files in question are also 44.1KHz mp3s and/or oggs, but I also have random background videos on. I would think that skipping would have more to do with the hard drive and the fragmentation of it rather than your computer specs.
So do i have to install something to make it work?
Google for Goldwave or Audacity. Goldwave is free as a trial but it's good. Audacity, however is free and fully functional. Refer to their manuals for resampling or adjusting the sample rate.