I had a similar reaction with my work Dell Laptop. We had to have a memory chip replaced to get going again.
Agreed. Memory. Try accessing the memory chips first and removing then re-seating them. Sometimes that works. If not, get new ones. Or get a bootable CD that has a memory test on it to determine which one. Usually there are two in a Dell laptop.
Same thing recently happened to my desk top. Yep, memory stick replaced and all is well.