Question : IE 8 Problems

System running Windows XP Media Center. When this updated to SP3 part of the package was IE 8. After reboot When I tried to open IE 8 I got an error message that read "The Instruction at 0x71ab4a83 referenced memory 0x71ab4a83. Memory could not be written.." I then have the option to terminate the program or to Debug it.
Once I close that window there is a Dada Execution Prevention window below it that  tells me that Windows has closed IE 8 in order to protect my computer.
I went to Control panel and Add/Remove Programs with the intent of rolling back to IE 7 but there is no remove button available.
How do I roll back to IE 7 under these circumstances? Will that solve the problem?
I know I still have Internet access because I can update my antimalware and antispyware applications and Windows updates still download themselves.

Please advise.

Thank you!

Robert

Answer : IE 8 Problems

Reset IE settings using MS fixit
http://support.microsoft.com/kb/923737

If still having issue run Combofix and post log
http://www.bleepingcomputer.com/combofix/how-to-use-combofix