K8N Neo2 Platinum troubles.

Question

This will be my first post here, and I hate it to be a problem post.  Anyway, I built my own computer about 2 months ago, and I seem to have a problem with 2D applications.  Here is my setup before I show you what I mean.
Mobo MSI K8N Neo2 Platinum
CPU Athlon 64 3000+ S939
PSU Antec 350W
GPU PNY Geforce 6800GT 256MB AGP
200GB Maxtor SATA HD
Sony DVD-RW
1 GB Mushkin PC3200 DDR Ram
OS Windows XP Pro
Ok, here is my exact problem.  I seem to have trouble playing most MPEG, AVI, and WMV video types.  I say most, because some will work ok.  I have a picture of my problem here:http://img.photobucket.com/albums/v281/ZeroX585/hmm.jpg
There seem to be lines that appear across my video, and some 2D games such as Doom, Zsnes, and Worms world party.  They also seem to appear when certain colors are shown during playback of videos and games, (mostly the darks and blacks.)  3D games work FINE, (Half Life 2, Doom 3, Far Cry are perfect).  No errors what so ever.  I have also noticed that this happens also when the program is dependent on some DirectX resources.  I have uninstalled and reinstalled DX9 about 3 times, I have my latest Graphics drivers, I have my latest Windows Updates, I have the latest Mobo chipset drivers and such as well.  I have also installed Windows XP again.  I am not certain that this is a complete motherboard issue, as I do not have parts to switch out, but I am lost as to what I can do next.  I HAVE replaced the GPU with an older ATI Radeon 9000, and it still happens.  I highly doubt that the problem would lie within the CPU, but it's probable.   I have reseated all the parts in the computer, and checked over my motherboard to make sure there isn't any damage to it.  I am lost as to what I can do next though.
There is one thing I have noticed though, is if I go into my Display Properties and take the Hardware Acceleration tab down to "Disable all Direct 3D and Direct Draw Accelerations", the 2D programs work FINE.  But if it goes even one notch up, it goes back to the lines.  Anyone know what this could be related to??  Thank you for your help.

Answer 1

Before I had my 6800 GT, I was using the Radeon 9000, and I did use Driver Cleaner 3 to remove the Radeon driver.  I also used Driver Cleaner when I update the Nvidia drivers, and I've done this a few times as well.  I've tried using the Nvidia direct drivers (Current version), and I am currently using the PNY version of the Nvidia drivers, all the while using Driver cleaner to remove the old drivers before installing the new ones.  I have not tried any games or videos in safe mode though, I think I will do that.  I will get a screen shot of Doom if I can.   By the way, I am not certain what you mean by "Be sure to run the Nvidia option, not the Nforce option."