Display Resolutions changed for Mac after creating Bootcamp

I've just deleted an old Bootcamp and created a new one with XP Professional. After installing software and updates I returned to the Mac partition to find that the choice of display resolutions had changed and I couldn't use the resolution I'd had before? Why would this happen?

Installing XP in BootCamp would have nothing to do with the resolution when you boot back to OS X. It would be coincidental.

What Mac do you have and are you talking about the screen on your Mac or an external monitor?

A pic of the display pref pane would help.

That's what I would have thought but it has changed. I have a Mac Mini with an external Acer V173 display and enclose a screenshot of the display resolutions choices which are missing some lower resolutions that I preferred. Why?

Not sure why those would be missing. Have you clicked on the 'Detect Displays' button?

I would also try a reboot again if you haven't.

I've tried both those things without success.

I've seen stranger things repaired that it should in no way affect, so I'd probably try Repair Permssions.

Next would be a PRAM /NVRAM reset. This can definitely affect display resolution.

Sorry. I'm new to Mac and far from being an expert. Can you explain exactly what you mean and how to do it. Thanks.

Try the NVRAM/PRAM reset first - click on the link in the post above for "how to".

Thanks. I tried that but it didn't change anything. I tried it twice.

And now I tried repair permissions after googling it and it did repair something but didn't change the display resolutions!!

The only other idea I have would be related to the monitor itself.

Some of those resolutions are not even supported by that monitor as it's not capable of anything over 1280x1024.

Next things I'd try - shut down the computer and monitor - disconnect all cables, whether they look and feel like they're connected or not - reconnect them - turn on monitor first, then computer.

Also check in the monitor's OSD and change it to Standard Mode if not already - prior to the above.

Thanks for all your help. Can you clue me in how to do the last bit, check the monitor's OSD?

couple of screenshots of the manual available here:

Still unchanged . . . thanks for trying. Maybe I'll phone Apple support in the morning.

Sorry, don't know where else to go from there.

I went away for a night and switched off and unplugged everything. When I came back today I turned on the Mac and my display is fine, back to normal, although the background picture is one I'd used a while back maybe before setting up Boot Camp. Don't know why? Any ideas? Anyway it's sorted out and thanks for your help.

Well, glad it's all sorted - another trick to add to the bag.

Am guessing you're using extended mode instead of mirroring.

Had mine do that. Never tried to fix it because I was only using it when I wanted to watch a movie on the TV. My only guess was that the extended desktop maintains the desktop picture that it had at the time mirroring was turned off.

Give a try turning mirroring on, then back off and see if it keeps the new desktop image.

Interesting but maybe you forget I have a Mac Mini and therefore my display is the only one. I don't have access to mirroring or extended controls.

I *think* I remember something like this happening to me a while back. No explanation or reason for it, and nothing else happened since.

Mikethebook said:

Interesting but maybe you forget I have a Mac Mini and therefore my display is the only one. I don't have access to mirroring or extended controls.

Click to expand...

Yeah, I did forget. Senility poking it's ugly head out again.