screen goes berserk after fresh XP install/reboot

[evd]

My system:

Intel Pentium4 2.4GHz 800MHz FSB
Gigabyte 8IPE100Pro mobo (Intel 865PE chipset) F6 BIOS
Sapphire Radeon 9600Pro video card
Seagate 80G SATA HD mapped to IDE0 Master (SATA0 mobo port)
Lite-On 16X DVD-ROM/48X CD-ROM as IDE1 Slave
Lite-on 52X/32X/52X CD-RW as IDE1 Master
Dell UltraSharp 1800FP 18'' LCD Monitor (connect w/ DVI cable)
Windows XP Professional

I just installed XP, relatively painlessly despite what I've been reading on the forums about getting it to boot from SATA drives. When I'm through with the install, it adjusts my monitor resolution and everything seems normal, except there is nothing on the desktop besides the Recycle Bin - no My Computer, nothing. However, I am able to explore my C: drive and see the DVD/CD-RW drives.

Then I restart the computer from XP, it boots up normally, except when it's time to start windows, the screen goes berserk. It splits into two areas, the upper one being black, the bottom one has these horizontal lines, like an old tv that can't get reception except thinner. Every couple seconds the screen fades out into complete black, sometimes going into power saving mode I think, then comes back with the lines and split screen...in other words, acts in a generally unsavory fashion.

I have not installed any drivers yet for the mobo/video card/monitor, so perhaps that accounts for it, but that still doesn't explain the (almost) blank desktop upon install, or how i can get windows to start so i can install the drivers... Or maybe this is a SATA issue...or something else entirely...

Can anyone help?

Thanks!