What is causing my system to wait 10 minutes after boot before presenting a UAC elevation prompt?

Question

Since about four days ago, every time I restart or reboot my Windows 7 machine, the system comes back up with Microsoft Security Essentials disabled. The network and sharing icon in the status bar appears with the teal-colored ring over it.

Entering the Network and Sharing Center from the icon takes extra time, but when it appears, there is nothing in the active networks list. This is ironic, because testing the network by pulling up websites in Chrome works just fine.

Next, I tried to start CPU-Z, which requires UAC elevation. I started it from an icon on the desktop, which caused the pointer to get a teal ring on it. At that point, Windows Explorer and all the desktop icons stopped responding.

I tried another elevated app from the Start button app list. Same result, only that time the Start button UI stopped responding.

So, I tried Task Manager, through the ctrl-alt-del mechanism, which worked, but clicking on "Show processes from all users" resulted in the same behavior: Task Manager UI stopped responding altogether, including not permitting the UI to move around on the screen though I was able to start other TM instances. Curiously, the "frozen" TM still updated its list of running processes.

10 minutes after trying all this, all the UAC prompts I expected appeared, the status bar changed to report that MSE and the network were working fine, and everything seemed to return to normal.

What could be going on?

Answer 1

Scan the disk using a disk utility such as Spinrite to ensure that the disk is readable.

Then try Soluto (to find slow startup suspects).

Answer 2

If you suspect malware see this post.

If there is no malware, then enable boot logging and then restart the system, then have a look at the logs when the system becomes responsive

Answer 3

This can always be some installed product that takes 10 minutes to initialize itself after boot. Security products would be my first guess.

You can test this by booting in Safe Mode. If this fixes the slow-down, then try to turn off one by one (or several at a time) all products that startup with the computer until you find the guilty one. Autoruns for Windows is best for this, as it can undo actions and also can take a backup of the existing startup applications. But better create first a system restore point as an additional protection.

If this does not help, then something is very wrong with your computer and needs repairing. Malware can never be ruled out, but a damaged system is more likely, as Windows Update can also break your system.

I would start repairs by How to Repair Windows 7 System Files with System File Checker. This requires a Windows 7 installation DVD of the same service-pack level as your installation.

If SFC has found nothing, the next step would be Repair Install. This will only refresh Windows without affecting the installed applications.

If you get your system working again, do Windows Update manually, rather than letting it do so automatically, just in case.

But take backups and ensure you have all the materials necessary to reinstall everything, or that your computer has a recovery partition, since the repair itself might make your computer unbootable.

Answer 4

@harrymc's answer was very useful, but a few days later I noticed that Windows Defender and Microsoft Security Essentials appeared to be in a race condition: The WD service was starting and stopping every few seconds. This might be the cause of all the delays, but I can't tell.

Answer 5

Turn off secure desktop and see if that helps.