Oops! How do I uninstall 32-bit Windows 7 & install 64-bit Windows 7 in its place?

I thought there were two installation disks in my Windows 7 box... then I noticed one was 32-bit and the other 64-bit. The 32-bit version is currently installed and I would like to delete/uninstall it and replace it with the 64-bit version. Poking around hasn't gotten me anywhere, nor has Parallels help. Anyone?

Thanks in advance!

 

Delete/Remove the VM and start again with a new VM.

 

Thanks for your reply, but I can't find the "delete VM" option.

 

Found it! In Parallels menu, choose FILE > REMOVE.