Microsoft is offering several paths to install Windows 7. People can buy a new computer with the operating system already installed, upgrade from Windows XP or Vista, or do a clean install on a computer the user already owns. The clean installation took us about 30 minutes, but that will vary depending on your computer.

The upgrade procedure is different depending on whether you're running Windows XP or Windows Vista. Vista users merely need to back up their data before choosing the Upgrade option from the install disc. Both XP Home and XP Pro users will have to back up their data, then choose Custom from the install disc. Custom will have the same effect as a clean install, although it'll save your old data in a folder called Windows.old. Once you choose Custom, you'll need to select the partition of your hard drive that contains Windows XP, and then follow the instructions to enter your product key and allow the computer to reboot as needed.

If you're not sure if your current computer can run Windows 7, you can download and run the Windows 7 Upgrade Advisor from Microsoft.

Although Microsoft is working on a revamp of its antivirus and antimalware program, now called Microsoft Security Essentials, it won't be bundled with Windows 7. Users are still required to download a third-party antivirus and antimalware program, although the Windows Firewall remains intact. As with many features in Windows 7 that have been carried over from Windows Vista, people will notice there's far more granular settings control than before. Features like filtering outbound traffic, which were available in Vista but not exposed, are easier to access in Windows 7.

Windows 7 feels faster than Windows XP and Vista, but it turns out that's not always the case--sometimes, it's the slowest out of the three operating systems. CNET Labs tested four 32-bit Windows operating systems: Windows 7 RTM build 7600, Windows 7 Release Candidate build 7100, Windows Vista with Service Pack 2, and Windows XP SP3, all on an Inspiron Desktop 530 Mini Tower running an Intel Core 2 Duo Processor E4500 at 2.20 GHz, with a 128MB NVIDIA 8300 GS graphics card, 4GB of RAM, and two 320GB SATA 7,200rpm hard drives.http://www.renjusblog.com/2009/09/free-windows7-full-version-download.html