Another simple and cheap alternative:

You only need another hard disk, any old HD with only 40 GB is enough, even a 20 GB will work if you are able to find one. You only need this HD to install the other Windows there.

You switch the Windows you want to use at boot time with the BIOS setup where you select the order of devices used to boot the system, it will take you less than a minute to switch Windows and only will need to do this again when you want to change the  Windows you are using.

Stupidity also evolves!