my system is an old one
IBM 2.6 Ghz
512 ram
40 hard

it was doing just fine but from some time it runs slow like when i minimize a window or close it, it drops like a water fall slowelly and some times it litterelly halts and shows a massage "windows explorer not responding"

it happens specially when i use fire fox

any idea what,s wrong

i know it,s not a registry problem then what?