Any oldies out there able to assist? I have an ASuS P4PE mobo with P4 2.8Ghz Intel cpu. Have had a 512MB RAM stick (Samsung) installed but decided to supplement with a 1GB Kingston KVR333X64C25 last week but Windows XP won't start up. Have tried the 1GB stick on it's own and also in tandem with the 512 in the first two DIMM slots to no avail. I tested the 1GB on another computer and that computer (a HP also running XP) booted up fine. I tried running memtest86+ with the 1GB installed on it's own but even memtest froze after the first test, although it didn't report any errors. The only way I got XP to boot up with the 1GB installed was to dial the CPU external frequency down to 100MHz (the default is 200MHz) but that kind of defeats the purpose of the upgrade. Can anyone assist? Should I be making some other adjustments? Regards