I purchased 2 256MB SDRAM PC133 DIMM 168 Pin Double Sided (Low Density) for a HP Pavillion 512N. I bought from comtread.com. I used there memory tool to check what memory I should buy. I also checked crucial and it came up with same ram. I install them and then plug in and start computer. The computer tries to boot up but then restarts again. I figured it was the ram then I took out the ram and put the original ram back. I still had the same problem. I can get into the bios by hitting the F1 key. It shows the ram is at 512MB, but is says PC100 not PC133. I tried putting default settings in the Bios. I try safe mode but when computer tries to start it just restarts again. Has anyone seen anything like this and have any ideas?

try and reset cmos while unplugged from the wall outlet.....make sure your ram is in the rght way Please keep us updated so we know if we helped you or not.

That was the only thing that I haven't tried yet.

Tried resetting CMOS still having same problem. Can RAM cause this problem or did I hit something that I am not aware of? I was very careful and all cables are properly attatched where they should be.

try starting with the bare minimum..like hdd and ram then adding in floppy and cdrom one at a time to see if it is something else. something like a bad cdrom drive can cause it...see if that helps any Please keep us updated so we know if we helped you or not.