Hi, On my Windows 7 laptop sometimes (still not sure what triggers this) mouse starts behaving the following way. I can still select application windows using Alt+Tab but when I click inside currently selected window it looses focus (judging from change of color of the title bar) and thus mouse is unusable. Nevertheless mouse works on Taskbar, but when I open hidden icons on notification area, it doesn't. I can get out of this misterious state by pressing Ctrl+Alt+Del. In that window mouse starts working normally and I can press Cancel and proceed normally. To investigate this situation I wrote an utility that displays window handle and title of active foreground window (as returned by GetForegroundWindow()). When the described effect is observed my utility shows that focus goes to window with handle zero. That's unfortunate because I was hoping to track offending process by using that window handle. I would greatly appreciate any suggestions of ways to track down the root cause of the phenomenon.WBR O.Z.

It sounds as if another program started. What processes are running? Try making a detailed list before and after it happens.Have you run a malware check on your system lately?What do the system event logs say? I don't usually find answers there but it's always worth looking.Standard questions: Is your security software up to date? Do you have any Explorer extension applications installed?-Noel

I'm running Comodo and it didn't report anything. As I've mentioned in my original post I suspect some other process too, but I need an insight how to identify it. Capturing window handle didn't work.WBR O.Z.

This issue can be caused by incompatible Windows Explorer plug-ins. Please use ShellExView. Important Note: Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information. Run ShellExView, in the pane sort the entries with manufacturers. Disable all non-Microsoft *.dll files, and check the result. If the issue does not occur, one of the files can be the culprit. We could narrow down it one by one. Regarding the last question, we could simply click the folder you would like to locate in the address bar. However if the ShellExView does not help, I suggest you create a new user account and see if the issue exists if you log on with the new account. If the issue persists with the new user profile, please disable all startup items and third party services when booting. This method will help us determine if this issue is caused by a loading program or service. Please perform the following steps:1. Click the Start Button type "msconfig" (without quotation marks) in the Start Search box, and then press Enter. Note: If prompted, please click Continue on the User Account Control (UAC) window.2. Click the "Services" tab, check the "Hide All Microsoft Services" box and click "Disable All" (if it is not gray). 3. Click the "Startup" tab, click "Disable All" and click "OK". Then, restart the computer. When the "System Configuration Utility" window appears, please check the "Don't show this message or launch the System Configuration Utility when Windows starts" box and click OK. Please test this issue in the Clean Boot environment, if the issue disappears in the Clean Boot environment, we can use a 50/50 approach to quickly narrow down which entry is causing the issue. Arthur Xie - MSFT

After some more observations I'm pretty sure it is my bluetooth mouse triggering the behavior. When I turn my mouse OFF I observe exactly the effect I've described. Usually I turn my mouse OFF along with the laptop so I didn't notice the connection before and as I understand mouse sometimes reconnects and these are the moments of mysterious behavior in question. I still interested in finding out the nature of the behavior in question. WBR O.Z.

Hi All, I have a similar, if not identical issue on a dell latitude e4300 notebook - vista business sp1. On startup is see this "lost focus" behaviour. In fact I am able to get mouse/trackpad functions on desktop items, but open windows and the taskbar do not respond. I haven't carried out any deeply technical tests, but I can say that any interaction with the UAC resolves the issue, and turning off the UAC also resolves the problem. I can reproduce this on a fresh Vista business sp1 install. Nothing I install/update/reinstall helps apart from turning off UAC. Can anyone help? James