While booting everything seems OK system check is OK and goes to Windows XP Pro start-up screen then boom no signal. I booted into BIOS and checked power management settings=nothing. Booted into Safe Mode just fine...Safe Mode with networking and everything seems fine. RAM is good, ran virus checks/ad-aware/BHODemon/HijackThis and only came up with 1 Browser helper/toolbar, cleard that out and tried rebooting with lower resolution no change. Could this be a SP2 thing? Any sugestions/help much appreciated. Thanks much.

AMD Athlon XP 2600+ 1.9GHz
768MB of PC2700 RAM
120GB Seagate HDD
nVidia GeForce 4MX 64MB AGP video
Windows XP Pro SP1 Ver 2002

If you're using SP-2(your spec list shows SP-1), then did the problem start immediately after installing it?