Just nuke it with Linux to be sure.
I tried that with Linux Mint. The 32 bit versions would install and run but the 64 bit versions would not.
I’m using Windows 7 64 bit version now and have an Intel Core i3-2120 CPU @ 3.30GHz, so it’s not the CPU not being 64 bit. When I finish installing Mint and reboot, I see a message that there is no operating system. Luckily, I had backed up my hard drive with Clonezilla before I started monkeying around.