Clear the Help and Support Center session History

When you browse pages in the Help and Support Center, the session History is stored (like the Internet Explorer History). The History column contains a list wherein you can pick from a page that you have read in the past. The session history for your user profile is stored in file HelpSessionHistory.dat

To clear the session History, you may just delete the HelpSessionHistory.dat file from the following folder:
%USERPROFILE%\Local Settings\Application Data\Microsoft\HelpCtr
Click Start, Run and type the above path.
Before deleting the History file, make sure you close the Help and Support Center first.