Nvidia video problem related to windowed mode & AA

Hi all -I'm trying to get a new PC set up to run FS9, and optimistically, FSX.For now, I'm still working on FS9. The particular combination of going to windowed mode with AA set higher than 2 immediately sends the screen into fits, showing a greatly enlarged but very rapidly flashing view of only the top of the screen. In full screen all is fine, as it is with AA off or set to 2. FPS is good and it looks good.Any thoughts on this? Maybe I should instead ask if anybody knows of a particular older driver that works well with this card in a similar PC that I could try.Particulars of PC: AMD 4200 64 X2, 2GB, 250GB SATA HD, Nvidia 7300GT w/ driver 91.31.I always fly in full screen anyway, but need to window briefly to start RC4.I have a feeling the answer is in this forum somewhere, but I am having trouble searching it out -- probably in large part because different people describe the same problem using different words, making precise searching difficult.Also, everytime the PC boots I get a bubble message saying that "SLI multi-GPU rendering has been disabled." Well, the card is SLI capable, but the motherboard isn't, so there never was any SLI, and it has no reason to think that SLI has been disabled. The original on-board Nvidia 6150 had been disabled and does not appear in the hardware manager, so should not be causing any confusion. Anyone know how to convince the system that SLI never existed on this PC? Perhaps that would cure my other problem? Regardless of that, any answers are certainly most welcome, even if it's just directing me to an existing thread that already covered this subject.Thanks! ...DaveDave JonesFort McCoy, Florida USA