Update, Scan and Troubleshoot to Fix Windows Explorer
1. Rule out potential corruption or other problems caused by malware by running full scans with your antivirus and antispyware programs. Before running the scans, make sure the programs are updated with the latest definitions. Alternately, run the scans while in Windows Safe Mode to prevent potential viruses or other malware from interfering with the programs.
2. Download and install any outstanding Windows updates, including service packs. To do so, visit the Microsoft Windows Update Web page (see Resources) and use it to run a scan on your computer for needed updates.

3. Restart Windows Explorer if the taskbar does not appear on your Windows desktop (and you're not using the auto-hide feature). To do so, press CTRL-ALT-DEL to start the Task Manager (depending on your operating system, you may need to click 'Start Task Manager' after pressing those keys). In Task Manager, click File, click New Task (Run), type Explorer in the Open field, and click OK.
4. Determine if recently installed software is interfering with Windows Explorer. Although most programs will play nicely with Windows Explorer, occasionally problems can occur that prevent Windows Explorer from running as it should. If you recently installed one or more programs, try uninstalling each program (one at a time) to see if the problems with Windows Explorer cease. If they do, check with the program's developer for an update, fix or workaround.
5. Perform a System Restore if you cannot locate a simple fix for Windows Explorer problems. To access this utility, click Start, All Programs, Access, System Tools and then System Restore. Choose a restore point prior to the time when you started experiencing problems with Windows Explorer.