Years ago I upgraded from 32-bit Vista to 32-bit Windows 7 Home Premium on my home theater computer. Now I want to go to a 64-bit OS to allow me to add more RAM to my existing 4Gb (not all of which the 32-bit version can address). Should I buy another Upgrade pack to go to Windows 8.1 Pro 64-bit? Or can I simply convert my computer to 64-bit by using the 2nd, 64-bit DVD version of Windows 7 Home Premium that came with my earlier update package? My motherboard and system components are all capable of 64-bit operation. Thanks!
Using the 2nd 64-bit upgrade disc is perfectly fine. The only thing to note is that when you change from 32-bit to 64-bit it's not an upgrade that's performed, it's actually a clean install (even though you're using and upgrade disc) because you're changing the architecture of the system. Use the migration wizards and take note of your settings and backup any files you cannot afford to lose as you're basically starting the system afresh.