Windows 7 RC (Ultimate) has been on my laptop for about 5 months. I have installed several times and in several different ways. After switching HDD, tried installing the 64-bit version.
Below are my words of wisdom.
If your pc originally came with a 32-bit OS, you know that a driver is available for that hardware setup. Already, there may never have been a 64-bit driver for that same equipment. If there was, you may now need an updated versioon if switching to a 64-bit version OS.
With more laptops and mobile users today, what about some of the programs that came with the system that didn't come with separate disks? For all of the above scenarios, it is recommended that Windows 7 be installed as an upgrade from your current system.
Anyone not appreciate the performance and feel of a clean install? If you are using Vista, I recommend reinstalling it as a clean install, with the discs that came with your system (think laptop). With all of your favorite OEM software, drivers and fully functional system intact perform the upgrade to Windows 7.
Clean, fast and everything that you were hoping for. Data migration aside, and most of this is nearly automatic these days (albeit time-delayed), the upgrade is complete. If you want to clean install Windows 7 or try a 64-bit version, there are still going to be issues of drivers that are unavailable or difficult to find. Also, be aware of programs that may no longer function at a higher level or need to be located on the OEM disk in order to reinstall. Again, with Windows 7, the choices are yours.