Try this. No, reinstalling Windows is the last big step to resolve this issue. Try just a few more things first, OK? Do this stuff in order of appearance restarting your computer after each step, if not prompted to.
Internet Explorer 5.x/6.x comes with a repair tool. To use it, go to the Add/Remove Programs Control Panel; Scroll and click to highlight 'Microsoft Internet Explorer 5/6.x' in the Install/Uninstall window; Then click on the Add/Remove button; Select 'Repair' the current installation of Internet Explorer radio button; Click on OK. Restart your computer when prompted.
Open Internet Explorer (IE); Tools menu; Internet Options; Advanced tab; Click the Restore Defaults button; Click Apply; Click Ok. Close IE.
Open (IE); Click the Tools menu; Point to Internet Options; Click the Security tab; Click the Default Level button; Click Apply; Click Ok. Close IE.
Open IE; Click the Tools menu; Internet Options; Click the Security tab; Click the Custom Level button; Click Apply; Click Ok. Close IE. Start IE as desired.
Get, install, update and run free Ad-aware (and its HexDump plug-in) from http://www.lavasoftusa.com/software/adaware/
First in the main window look in the bottom right corner and click on Check for updates now and download the latest referencefiles.
Make sure the following settings are made and on -------ON=GREEN
From main window :Click Start then Activate in-depth scan (recommended)
Click Use Custom Scanning Options' then click Customize' and have these options selected: Under Drives and Folders put a check by Scan Within Archives and below that under Memory and Registry put a check by all the options there.
Now click on the Tweak button in that same window. Under Scanning engine select: Unload recognized processes during scanning and under Cleaning Engine select: Let windows remove files in use at next reboot
Click proceed to save your settings.
Now to scan just click the Next button.
When the scan is finished mark everything for removal and get rid of it.(Right-click the window and choose select all from the drop down menu and click Next)
Restart your computer.
Tell me what anti-virus you use please? I know of an excellent freebie called AntVir I use that might solve some issues for you. You must get AntiVir ( http://free-av.com
click the Download button then click the red/black AntiVir icon), uninstall your current AV then restart your computer then install AntiVir. If you decide to go that route.