You know what, this exact problem happened to me. And im still wondering how to fix it.. I got a startup disk, re formatted, partioned my drive. Tryed installing 3 differnt windows versions (98, 98 SE, ME) and whenever it says i think "Prepaing install wizard" or whatever is the thing that start loading at the beginning, when thats 100% my computer just crashes. And floppy light is stuck on. Someone reconmended me a program called Docmem to check memory. I run the quicktest and after it gets to 100%, crash.... I got 2 new ram modules from friends. Still crashes... L2 Cache? Only 1 Western Digital HD, jumpers are right, cables in, it was ME that i had installed, then one day i crash, when i boot up again i get "Non System disk press any key" or about that.... And still whenever i boot up without startup disk it says that.