Try this to completely uninstall MSIE 8 (even if you think it is removed):
http://support.microsoft.com/kb/957700
Reboot.
Then, do this to uninstall MSIE 7:
http://support.microsoft.com/kb/927177
Reboot.
Now, try this to install MSIE 7:
http://www.microsoft.com/Downloads/details.aspx?familyid=9AE91EBE-3385-447C-8A30-081805B2F90B&displaylang=en
Reboot.
Should work okay, but FireFox is less error-prone and faster.
Firefox is the bomb. I’ve been using it since 2003.
YMMV. Depending on the number of add-ons and extensions, this is true. The more Firefox extensions and add-ons are installed the more bloated and sluggish Firefox becomes.