Hi Barbo1000,
Step1: Follow this step and check if it fixes the issue.
Important: This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
How to back up and restore the registry in Windows KB322756 (http://support.microsoft.com/kb/322756/)
1. Go to start and type regedit.exe.
2. Navigate to the following location: HKEY_CURRENT_USER\Control Panel\Desktop.
3. Double click the 'ForegroundLockTimeout' key. Change the notation to decimal.
4. The default value should be 200000 millisecond in decimal, or 200 seconds. Click OK.
5. Restart your computer and check if the issue persists.
Step 2: Create a new user account and check if the issue persists.
Refer this link to do the same:
Create a user account
**http://windows.microsoft.com/en-us/Windows7/Create-a-user-account**
Regards,
Divya R – Microsoft Support.