A nice, safe way to mess around with the Windows 7 beta is to set up a dual boot system.
1. Create an image of your hard drive. Just in case. For this, you’ll need an external drive with enough free space to hold your image (at least the same size as the drive you’re cloning, and a LiveCD of PING – PartImage Is Not Ghost. Boot into the LiveCD, and start the imaging process. This can take a couple hours, depending on the size of your drive. You’ll have a sector-by-sector backup
2. Create a new partition. You can do this with the free Easeus Partition Manager Home Edition, or the live CD for GParted. I’ve used both tools without any problems, but be careful on your own.
3. Download the Windows 7 Beta, and get a key, too. The beta program has been extended until Feb 10. Burn the ISO to a DVD (it won’t fit on a CD), then run the installer. You can either boot from the DVD, or start the installer directly from within Windows XP or Vista. When it comes time to choose where you want to install Windows 7, make sure you choose the new partition, not your current one!
The downloads of PING, GParted and Windows 7 are all ISO images. If you need a free tool to burn ISOs to CDs or DVDs, I strongly recommend Imgburn.
If you don’t have a DVD burner for Windows 7, you can mount the ISO as a virtual drive using Pismo File Mount, and then running the installer from the virtual drive. This works because the Windows 7 installer can be run from within Win XP or Vista. You can’t do this for Easeus, GParted or PING, since you need to boot out of Windows to make the changes.