Symptom - can move mouse, but cannot switch focus between windows; focus will be stuck on a window until CTL+ALT+DEL pressed. This un-freezes things so that user can then left click in another window to switch focus to that window. (This usually works).
Tried so far: Uninstalling and re-installing many of the programs; updated several key drivers. Same temporary freezing of the focus.
Then we tried restoring an Macrium image of the entire C:\ drive from August 2011, long before this problem first occurred. We had no luck. There was the same intermittent freezing of the focus.
We've run HDTune to check the HD - all seems ok and green on every tab. We ran Windows Memory Diagnostic; this was all clear as well. I am open to running other types of scans.
We ran two separate malware scans - the latest and updated ESET as well as the latest Dr. Web. No malware of any kind was found.
Then we became desperate and re-installed Windows 7 from disk. Before I could even load a driver from the motherboard driver disk, the focus froze again on a window. As always, we could still move the mouse around the screen, but clicking produced no result. We could not click on anything and had to CTL ALT DEL to regain ability to switch focus.
Some Speccy data:
MS Windows 7 Home Premium 64-bit
Intel Core i7 950 @ 3.07GHz 40 °C
Bloomfield 45nm Technology
12.0 GB Triple-Channel DDR3 @ 534MHz (8-8-8-20)
ASUSTeK Computer INC. SABERTOOTH X58 (LGA1366) 29 °C
NVIDIA GeForce GTS 250 (Microsoft Corporation - WDDM v1.1) (PNY)
244GB Western Digital WDC WD2500KS-00MJB0 ATA Device (SATA) 31 °C
ATAPI iHAS324 B ATA Device
Realtek High Definition Audio
Computer is my son's - he is not the same without it. Any help highly appreciated!