My PC keeps failing to upgrade to Windows x64bit.
Just for the record, you are not allowed to upgrade an operating system from 32bit to 64bit. That won't ever be possible. Secondly, if you have issues with the Windows Update, I recommend using the Fix it tool released by Microsoft to fix and diagnose errors that might prevent your computer from performing the necessary updates.
Download the tool: http://windows.microsoft.com/en-us/windows/troubleshoot-problems-installing-updates#1TC=windows-7