Why is UAC so slow to launch?
August 8, 2010 1:19 PM Subscribe
Why does it take so long for Windows UAC to come up?
Does anybody know what's responsible for the lag between issuing a command which requires elevation and Windows (7, though I notice this happens in Vista, too) coughing up the UAC elevation request? If it was just a moment, I'd understand, but I've seen it take up to five to ten seconds, making me wonder if the program I'm trying to launch has hanged, and it's even like that on faster computers.
Does anybody know what's responsible for the lag between issuing a command which requires elevation and Windows (7, though I notice this happens in Vista, too) coughing up the UAC elevation request? If it was just a moment, I'd understand, but I've seen it take up to five to ten seconds, making me wonder if the program I'm trying to launch has hanged, and it's even like that on faster computers.
Best answer: Microsoft says that video driver issues might cause the secure desktop to be slow in showing up, since I guess it turns off various graphic acceleration features which makes the video card do some mode-switching gymnastics.
I'd check if your video driver is up-to-date. Otherwise you can just turn secure desktop off.
posted by zixyer at 1:51 PM on August 8, 2010
I'd check if your video driver is up-to-date. Otherwise you can just turn secure desktop off.
posted by zixyer at 1:51 PM on August 8, 2010
I notice the same thing, usually about 5 seconds for me. I'm running an ATI 5700 series card with dual monitors in case that's relevant to the video issue. I also notice that if I launch a game, about half the time I get popped back to the desktop and have to click the game's icon in the taskbar to get back into it. It's no big deal, just kinda weird behavior I never saw with XP.
posted by barc0001 at 2:14 PM on August 8, 2010
posted by barc0001 at 2:14 PM on August 8, 2010
Best answer: Yeah, I've had the same problem and it seems to be very similar to the delay that occurs when my screen resolution changes.
I think disabling secure desktop is probably a bad idea - a better bet would be to go into your UAC settings and drag the slider down to the second lowest point ("do not dim my desktop") and see if that helps. I just did so and will report back one way or the other.
FWIW I have a Nvidia GTX260, regularly update my drivers, and have always had this problem in Windows 7.
posted by L. Ron McKenzie at 2:14 PM on August 8, 2010
I think disabling secure desktop is probably a bad idea - a better bet would be to go into your UAC settings and drag the slider down to the second lowest point ("do not dim my desktop") and see if that helps. I just did so and will report back one way or the other.
FWIW I have a Nvidia GTX260, regularly update my drivers, and have always had this problem in Windows 7.
posted by L. Ron McKenzie at 2:14 PM on August 8, 2010
Best answer: "do not dim my desktop" is the same thing as turning secure desktop off.
posted by zixyer at 2:19 PM on August 8, 2010 [1 favorite]
posted by zixyer at 2:19 PM on August 8, 2010 [1 favorite]
Zixyer is correct. My apologies.
posted by L. Ron McKenzie at 2:24 PM on August 8, 2010
posted by L. Ron McKenzie at 2:24 PM on August 8, 2010
Best answer: What it's doing is taking a screenshot of your desktop and making a whole new session for the prompt, but with the screenshot as your background (dimmed, usually).
This is all done to prevent automation by malicious programs. Software running in the user's desktop session can't, for instance, take a screenshot, find the "Yes" button, and move the mouse over there and click.
I think the slowness comes from:
posted by aubilenon at 2:32 PM on August 8, 2010 [1 favorite]
This is all done to prevent automation by malicious programs. Software running in the user's desktop session can't, for instance, take a screenshot, find the "Yes" button, and move the mouse over there and click.
I think the slowness comes from:
- Creating a new session is kind of heavy weight.
- Taking a screenshot can be slow - video cards are all optimized for transferring stuff to them. Some cards don't have any quick way to read stuff out of their memory. If you have an enormous desktop this is a bigger problem.
- A lot of this stuff isn't used very often, and so won't be sitting around using up valuable RAM, but ready to go. So some stuff may need to be loaded off disk.
posted by aubilenon at 2:32 PM on August 8, 2010 [1 favorite]
I just upgraded VLC and can verify that the delay is gone now that I've disabled secure desktop.
posted by L. Ron McKenzie at 2:33 PM on August 8, 2010 [1 favorite]
posted by L. Ron McKenzie at 2:33 PM on August 8, 2010 [1 favorite]
Response by poster: Excellent. Thanks for the help, folks!
posted by Pope Guilty at 3:48 PM on August 8, 2010
posted by Pope Guilty at 3:48 PM on August 8, 2010
This thread is closed to new comments.
posted by delmoi at 1:29 PM on August 8, 2010