This is Windows 7 SP1 ? Also is Internet Explorer updated to IE10?
This is important even if you use another browser as default.
Try running the McPreinstall.exe first then try the installer again: http://download.mcafee.com/products/licensed/cust_support_patches/Mcpreinstall.e xe
Also you must be signed in as a user with Administrative privileges to install the software.
Other thoughts: It may be necessary to remove Family Protection and then make BT Netprotect the first installation, followed by FP.
Uninstall in the normal way and then run the MCPR cleanup tool, reboot and then reinstall from your online BT account, followed by the FP
I have done what you have suggested, but unfortunatly it still does not install. Same error as in original post above.
That's not good. I don't know what else to suggest. Try Technical Support via the link under Useful Links at the top of this page. It's free by phone or online chat.