Problem with display settings

WinXP Home SP3 - first, this is not a driver issue, and doesn't belong in the driver forum (I have already tried everything driver related and nothing worked so I'm sure it's a Windows problem). The video card is an aging NVidia Riva/TNT2 AGP card in an aging HP tower. Here's the deal: when the system boots to the desktop, the display is fine, the system works fairly well (for a 6-7 year old PC), and things are OK. The screen saver kicks on, and does its screen saving, but upon exiting the screen saver, the display settings are reverted back to 'Low - 8 bit color' and the resolution is knocked back to 640x480 or 800x600. Under Display Properties, all the tabs are gone except for "Screen Savers"; if I run Dial-A-Fix, it brings all the tabs back, and I can change the color depth and resolution, but only until the next reboot, or until the screen saver kicks in, then all the tabs are gone and the color goes back to 8bit and the res back to 640x480 or 800x600. However- I can use the NVidia NView Desktop Manager to change resolutions and color depth (16bit, 32bit, etc), and that survives the screen saver. I'm running a malware scan now, but it's about 60% through and nothing found yet. When the scan finishes, I'll reboot and see if using the NView settings will stick and survive the reboot, but I still need to get all the tabs back in the Display Properties window.... any ideas, thoughts, or suggestions will be appreciated.
THANKS!
:-D

 

UPDATE - this is weird.... I turned my back to do something else while MalwareBytes is scanning, and the screen has gone back to 8bit and 640x480 res WITHOUT the screen saver kicking in!!! It did it ON ITS OWN without any input from me, and completely without warning or notice!

:banghead :cry

(I wish I hadn't turned my back 'cuz I'd have liked to have seen exactly what happened )

 

No gaming resolution software, like RefreshLock, onboard?

 

Nope. All malware scans have come up clean except for tracking cookies, which aren't a big deal and can't be responsible for changing display settings. I just completed a repair install of WinXP, and even THAT didn't fix the problem!! :banghead

 

There is no onboard video, and I did try a 2nd (and 3rd) video card, and all did the same thing. After talking to the owner of the PC, he said it was OK to format and reload, so that's what I did, and now it works fine (obviously). Apparently something deep in the registry was changing the settings. I did locate some registry settings cnofigured to disable some of the tabs in Display Properties; I think they were leftover from a malware infection a long time ago. All malware scans were clean, so these settings were either undetected and left over, or something was VERY corrupt.... whatever the cause, it's all good now.