svcd file conversion

i'm running xp pro,with an intel pentium II processor,348 mhz,and 128 mb of ram.as you can see,that's not a very powerful computer,which leads to my question.i can play svcd files,but the sound skips on and off and sometimes the video is very slow on those files.also,avi files dont play well,either,all other file types seem to work fine.what i want to know if is there a SIMPLE program that i could use to convert these files to asf,wmv,or mpg.any help would be apppreciated,thanks in advance