Try using System File Checker to scan your OS for missing/corrupt files:
1. Click Start, and then type cmd in the Start Search box.
2. In the results area, right-click cmd.exe, and then click Run as administrator.
3. At the command prompt, type Sfc /scannow, and then press ENTER.
You may also want to check out this link on how to solve the problem: http://www.techsupportall.com/windows-explorer-has-stopped-working/