gnotella system files update crashed win nt

I downloaded a clone of napster from http://gnotella.nerdherd.net/download.html--it is called gnotella .7...after donwloading it, i tried to install it on my win nt system and it said i had old system files and could not install...and asked if i would like to update them....so i said yes and then restarted my computer....when i restarted it looked like it was loading everything ok, (meaning the dots were loading at the top of the screen where it tells me how much memory i have and number of cpus), but when it was almost done loading the os, i got the blue screen of death and it said that my system has terminated...i have no clue what to do. I tried last know good configuration, but nothing...help! i lost some pretty important data...anything will help...thnx