Can't Install Windows 7 On To 64-Bit System. [SOLVED]

Windows 7 installed perfectly on to my laptop with no problems and after I tried it out, I decided to put it on my actual, good computer.
I currently have Windows Vista Business 64-Bit but whenever I try to install Windows 7, a compatibility report comes up saying that I can't 1) Install a 64-bit windows to a 32-bit system and 2) Can't install a 32-bit windows to a 64-bit system. This makes no sense to me and I'm wondering if anyone here would be able to help me with this issue?
Here's a screencap

Hello,

Which bit is your PC using? 32- or 64- bit?

I've got Windows Vista Business, 64-bit

Hello,

Vista.
So, at what point do you get the error? After choosing which version you want to install? (Home Premium, Ultimate etc)

I've tried Ultimate, 64-bit. When it's doing a compatibility check before it installs, it stops and says that message. It worked perfectly fine on my laptop -.-

Hello,

I wanted to say whether you could format your drive first and then install Windows 7, but the discs are missing the boot files...

I recently reformatted my computer if that has anything to do? I'm not sure if it will be a waste of time or not to try again because I finally got everything back on my computer (Games and stuff).

am i allowed to ask if this is a legal version of windows 7?

I've decided to stick with Windows Vista.

Windows 7 is known to have problems with Tablets and their pressure sensitivity and overall performance. Thanks for the help though.