Ok, you have Windows 7, either the 32 or 64 bit version and looked over the new features and either burned the image to disk or set it up on a 4 gig memory stick and are ready to jump in the deep end and install Windows 7. My advice is to do a CLEAN install on a NEW hard drive. 500 gb drive deals are usually available for about $50. Here is a "hot deals" discusion forum that I've found to excellent: http://forums.slickdeals.net/forumdisplay.php?sduid=38094&f=9&daysprune=7&icon=41&tagid=0&order=desc&sort=voteavg Fatwallet.com is also a good source to check for special deals. YOU WILL NEVER REGRET BUYING A NEW HARD DRIVE. Because: 1. All hard drives eventually fail. 2. The price is incredibly cheap. I've even seen deals for 1 TB drives for $50 including shipping. That's 5 cents/GB. My first "big" hard drive (30 yrs ago) was an 80 MB USED drive for $180. That comes out to $1,000 per GB !!! 3. A new SATA 7,200 rpm drive will most-likely be bigger and faster than your old drive. 4. When Win 7 is installed and customized you can EASILY copy your data from your old drive. 4. You will have a working BOOTABLE backup of your old system, should there be a problem with with your new installation. (For example: I ran a duplicat file finder and found a ton of files that were duplicated and I allowed it to delete the duplicates. In the process it deleted files that windows was using, rather than the ones that were the backup/extra. It was easier to reinstall Windows than to figure out how to fix the mess.) (Should you take advice from someone who did something so stupid? Take that into consideration when you read my blogs If you get a Western Digital or Segate brand the WD website has a link to a FREE version if Acronis True Image that works with these hard drive brands. This is an EXCELLENT program that will clone one hard drive to another making it bootable. More on that later but you may want to take that into consideration when you make your purchase. DEFINITELY get a 7,200 rpm drive! When you run the Widows 7 performance index the hard drive USUALLY has the lowest number. Slower hard drives decrease performance significantly. Open your system case and UNPLUG YOUR PRIMARY DRIVE (with Vista or whatever) then install the new hard drive. Boot and press "some key" to go into your bios and set the boot sequence to your usb or dvd drive and save the setting and exit. It should reboot into the Windows 7 install. Go to Custom and do the install... otherwise it will be trying to find a previous version of Windows to do an upgrade. You may have to use the tools and format the new drive first, but the install will probably prompt you if you need to do that. This is why it is very IMPORTANT to unplug your primary drive. You don't want ANY confusion about which drive you are formatting. When you install Windows you'll be prompted for a product key code. If you don't have one you can press enter and have 30 days evaluation (which can be extended 30 more days 3 times with "rearm" -- google Rearm if you haven't found a key code and activated within 30 days.) For educational purposes only, there have been discussions about methods that use "Activators" to "extend" the evaluation period of Win 7 from 30 days to forever. I do NOT recommend anyoue use these "methods" for piracy purposes. When the install is finished and new updates are applied you can disable/customize/tweak/modify a few dozen settings/features to make your system run/shutdown/reboot significantly faster. You may want to use a program like Driver Genius to verify your hardware has the latest drivers. And you can install a few third party utilities for extra security and personal customization. It's best to get the system setup and tested before you start moving you day-to-day working files and programs from your old system.