I just spent the weekend recovering my Windows 7 Ultimate/64 bit system from backups. My big mistake was allowing a couple of recent windows updates. I can't be sure which one (or ones) caused the problem. I've narrowed it down to one or more of the following:
- Internet Explorer 10 for Windows 7 for x64-based Systems
Update type: Important
- Security Update for Windows 7 for x64-based Systems (KB2807986)
Update type: Important
A security issue has been identified that could allow an authenticated local attacker to compromise your system and gain control over it. You can help protect your system by installing this update from Microsoft. After you install this update, you may have to restart your system.
- Update for Windows 7 for x64-based Systems (KB2791765)
Update type: Recommended
Install this update to resolve a set of known application compatibility issues with Windows. For a complete listing of the issues that are included in this update, see the associated Microsoft Knowledge Base article for more information. After you install this item, you may have to restart your computer.
I don't think it was IE10 but I'm not willing to do another recover from backups to find out.
After installing the above updates the Aero transparency effects are disabled and I couldn't figure out how to re-enable them. This isn't a big enough deal to bother recovering my system from backups. However, it is a highly visible symptom of more serious problems. The killer flaw was the fact that all my browsers (FF, IE9 and Chrome) became absolute sloths. They would load the initial page, but scrolling and refreshing content became unusably slow. I originally ran all the malware checks I could and they came up clean. I then tried to do a system restore, which failed, followed by attempts at earlier restores which also failed. Then I tried a restore from safe mode. Also failed. Finally I booted from my original installation disks, did a repair and tried a restore, this too failed. I actually decided to try an in-place upgrade but since my original disks are for Windows 7 Ultimate, and my current system is Win 7 SP1, the in-place upgrade will no longer run.
I finally restored from my Acronis True Image backup (had to boot from my USB Acronis drive). When that completed, I re-installed some applications (notably Visual Studio 2012 and associated plug-ins). I rebooted multiple times and everything appeared to work well. I made a new backup. Then I ran a windows update, installed all the important and recommended updates and the problem immediately returned. Another restore from backup, followed by updating everything but the above three updates and all is working well again. If anyone has any further information, or has narrowed this down I'd be interested to hear from you.