Solved Screen resolution flips back and forth at start-up

When I start Windows Vista up the desktop screen will do either one of two things: a) come up normally, then flash to a smaller resolution, with giant icons, and then flash back to my normal resolution--with the icons now realigned either along the top or the left, because of that resolution reset--or b) come up with the wrong resolution first, big icons and all, and then go black and flip to the normal resolution--with the icons of course reset. (I think it goes to black every time it switches, btw.) I have googled a lot about screen resolution changes being a problem with the fast user switch function, although nothing that quite aligns with my version of the issue. It happens without switching anything, although it does seem like it is related to the fast user switch function bc of the following:
Last week I went on vacation and had someone watching my dogs...I turned on guest account and had her log in as that. The first time she used it there was no start menu to log off with, and she shut down manually. The other few times she was able to shutdown onscreen, and that was that. The times I have turned on the guest account and gone in there, hoping that exiting and turning it back off will somehow restore things, there was no start menu (it's like the screen resolution made everything so large most icons and the start menu are offscreen somewhere), and I used cont-alt-del to switch back to my normal user profile. This has changed nothing. System restoration to a day, even two before I set up the guest account and she started using it, did nothing (I have since restored it back to today's point). It was fine before I left, and it has been screwed up since I came back, so I think it must have to do with the guest account somehow...
My normal resolution is 1280 x 1024 (60hz, 32bit). I have two monitors, but the other has not been turned on during a single part of this whole problem. Not really a computer guy, so if there is something else I should be telling you, please just ask. Thanks so much.

Welcome
Go to search, type device manager. In device manager look for any yellow warning markers by the drivers. If none, make sure that the monitor and graphics driver is up to date.
If that is not the solution.
Make a full updated anti virus scan.
Donwloand and run a full scan with malwarebytes.

Not the best way to install a driver, but will work in a pinch.
http://www.vistax64.com/tutorials/193584-device-manager-install-driver.html

Well, I didn't have any yellow warnings. I ran malwarebytes and it found a few "adprofessional" things that I let it take off. A TrendMicro scan turned up nothing (all my friend did was check her email, btw, so I don't think she could have downloaded anything anyway). There is a Windows update for my Nvidia driver. My current one is 8.17.11.9621. I have ignored that one for a long time because it had done something buggy before, but I figured what the heck, and let it update the driver like it wanted to do. All hell pretty much broke loose. The monitor basically blacked out, so I had to manually shut down, and when it restarted (it took a few go-rounds of start-up before the welcome screen/desktop finally came up, probably bc malwarebytes was trying to reboot as well to complete the purge) it wouldn't create the NVIDIA display panel, saying it could not be created: possible version mismatch, etc. I rolled back to the old driver, or tried to, but somehow I think I may have clicked an extra "ok" button, and it took off NVIDA completely. At that point I did system restore, and now things are back to normal screwed up. Maybe I should have reinstalled NVIDIA from scratch instead, but I wasn't sure how, or if that was a good idea, so I did the restore instead. I looked up the monitor driver and the newest (only?) one has been around longer than I've had the computer, so I don't think that's it. NVIDIA has been working fine all this time anyway, until the guest account business...

I downloaded (from someone who posted it to megashare, since NVIDIA doesn't offer it anymore) the driver that I have been using, and that I restored to after the disasterous update. Should I "refresh," if that's the right word, my current version with this new one? What would be the best way to do that if so?
Barring that, any other thoughts on what avenues I might chase? Again, I know screen resolutions are a common problem re: the switch user function, although mine seems to be a different version of that...

Make sure that all the nvidea setting and properties are set to default.

Just in case you don't know how: Control Panel > Nvidea Graphics Media >
settings

While your there check the Display Settings Tab and the Aspect Ratio
Options, which should be set to maintain aspect ratio.

Just remove the Nvidea Graphics monitor through Control Panel >
Device Manager > Click + at Display adapters > right-click Nvidea Graphics > Uninstall > Restart Computer

Now, when you restart Vista should go through the "found new hardware" setup and then look for drivers and reinstall. Just in case it doesn't then save the driver install package in your documents so you can get to it and install the drivers manually.

If all that doesn't short out the problem.

Just goto task manager and check (Show processes by all users); is there any process like "taskeng.exe". if found then fix it (End this process).

Hope this works. Good Luck.

Post your result. Thanks

Thanks richc46, and thanks Arvinwebb. I didn't have to follow the last bit about reinstalling NVIDIA bc the last two boot-ups have been fine. Apparently, my uninstall/ restore did the trick; I just hadn't done a fresh reboot since that. Incidentally, the prolonged bootup that made me think my computer had gone haywire was just the setup of new Windows downloads that had come along for the ride when I allowed it to install the crap NVIDIA driver. It did that again when I redownloaded them (after the system restore). Anyway, problem solved. Thanks so much for your help!

Nice to hear that your problem has been shorted out. You are welcome always pal.