Try this:
How to use Reset Internet Explorer Settings (RIES) (http://support.microsoft.com/kb/923737/en-us)
To use RIES in Internet Explorer 7 (http://www.microsoft.com/windows/downloads/ie/getitnow.mspx), follow these steps:
1. Click the Tools menu, and then click Internet Options.
2. On the Advanced tab, click Reset.
3. In the Reset Internet Explorer Settings dialog box, click Reset.
4. When Internet Explorer 7 finishes restoring the default settings, click Close, and then click OK two times.
5. Close Internet Explorer 7. The changes take effect the next time that you open Internet Explorer 7.
Note for users who cannot start Internet Explorer 7 for some reason, use RIES from Internet Options in Control Panel.
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And this one:
http://www.techspot.com/vb/post662504-2.html
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Then Restart, and then see if you can update (which is of utmost importance)