You may want to run a virus/malware scan, first off. http://www.kaspersky.com/virusscanner
In the meantime, you can add an exception for Explorer.exe in Data Execution Prevention.
1. Click Start, click Run, type sysdm.cpl, and then click OK.
2. Click the Advanced tab, click Performance, and then click Settings.
3. In Performance Options, click the Data Execution Prevention tab, and then click Add.
4. In the Open dialog box, locate and then click the program. (should be C:\Windows\explorer.exe)
5. Click Open, click Apply, and then click OK. When you are prompted to restart your computer, click OK.