You don't mention what the problem PC is running so can you post the operating system and service pack details, also what version of Internet Explorer is installed?
Uninstall everything via Control Panel.
Download and run the MCPR cleanup tool, listed under Useful Links at the top of this page.
Reboot and reinstall from your online account or the CD if this is a new suite you bought retail.
Customer Service (also linked under Useful Links) can sort out any licensing issues for you free of charge.
It is windows Xp home edition version 5.1.2600,service pack 3 build 2600.Internet exploer 8
The problem with the re-install,is that it doesn't accept my password.but it accepts my password to log in my account page.and i said i cannot activate Mcafee on her computer without that password working.
Also i noticed that on my computer if i download a file and right clcik on it to scan for a virus.I scans all of windows instead.is there a fix for that.Thank you for your help
Call Customer Service, or use their Online Chat. It's linked under Useful Links at the top of this page and is free.