Hi debba1,
Follow the methods listed below:
Method 1:
Start your computer in a clean boot state and see if that fixes the issue.
See How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7 for instructions.
Note: After troubleshooting, make sure to put the computer to start as usual as mentioned in Step 7 in the above KB article.
Method 2:
I’d recommend you to run a full system virus and malware scan on your computer.
Run an online PC safety scan using Microsoft Security Scanner from the link below:
Also see: Using anti-malware software to help protect your computer
Additionally, if you do not have an antivirus program installed on your computer, I’d recommend you to download and install Microsoft Security Essentials (MSE) from the link below: