Hi John,
When you click the Internet Explorer icon, window may flash a second and quits. Or, it may show an Error-Reporting dialog. This may be due to a malware Browser Helper Object which causes Internet Explorer process to terminate. If you see the Error-Reporting dialog, click "to see what data this report contains" and identify the Module Name causing this error. In most cases, it may be the spyware DLL. Therefore, reinstalling Internet Explorer [in case of a spyware DLL] may not help.
Sample Error-Report dialogs:
http://www.mvps.org/sramesh2k/images/EReport1.JPG
http://www.mvps.org/sramesh2k/images/EReport2.JPG
To test with: Disable third-party browser extensions in Internet Explorer
1. Click Start, point to Settings, and then click Control Panel.
2. Double-click Internet Options.
3. Click the Advanced tab.
4. Under Browsing, clear the Enable third-party browser extensions
(requires restart) check box.
5. Restart Internet Explorer.
If this helps, read here for further troubleshooting:
Cannot open Internet Explorer:
http://www.mvps.org/sramesh2k/IEFAQ.htm