Method 1: I would suggest you to I would suggest you to perform an SFC scan and then check- Perform a SFC Scan
Click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator. If you are prompted for an administrator password or for a confirmation, type the password, or click Allow
Type the following command, and then press ENTER:
sfc /scannow
A message will appear stating that 'The system scan will begin'. Be patient because the scan may take some time
If any files require a replace SFC will replace them. You may be asked to insert your Win7 DVD for this process to continue
If everything is okay you should, after the scan, see the following message "Windows resource protection did not find any integrity violations"
After the scan has completed, close the command prompt window, restart the computer and check.
Check the below mentioned link for further guidance on SFC scan -http://support.microsoft.com/kb/929833
Method 2: if the issue persists, I would suggest you to refer to the below mentioned link to fix a corrupted user profile and follow the steps provided- http://windows.microsoft.com/en-US/Windows7/Fix-a-corrupted-user-profile
For additional assistance you nay refer to the link - Create a new user account- http://windows.microsoft.com/en-us/Windows7/Create-a-user-account
Check if the issue appears in the new user account. You may also check after logging in as an administrator.
Method 3: If the hotfix you have installed is not very critical for your computer then you may use the below mentioned steps for system restore -
The System Restore tool uses restore points to return system files and settings to an earlier point in time. You can use it to restore the operating system to a point in time in which you did not experience the issue.
Note: When you use System restore to restore the computer to a previous state, programs and updates that you installed are removed. It is possible that your hotfix files may get removed.
To do this, there must be a System Restore point at which the logon was successful. Follow the steps mentioned below to perform system restore – To restore the operating system to an earlier point in time, follow these steps:
Click Start, type system restore in the Start Search box, and then click System Restore in the Programs list. If you are prompted for an administrator password or confirmation, type your password or click Continue.
In the System Restore dialog box, click Choose a different restore point, and then click next.
In the list of restore points, click a restore point that was created before you began to experience the issue, and then click next.
Click Finish. The computer restarts, and the system files and settings are returned to the state that they were in at the time that the restore point was created.
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