First, find a time when you won't be using your system for a while--say, three hours. Close any open programs, then select Start, Programs, Accessories, System Tools, Drive Converter (FAT32). Click the Details button, read all the pertinent do's and don'ts (for example, don't try to convert a compressed drive), then click Next. Select the drive you're about to convert, click Next, and wait as the wizard makes sure you don't have any incompatible programs installed. Click Next again, and you'll be asked if you want to back up your files before proceeding. If so, click Create Backup and so on (Microsoft Backup will help with the operation); otherwise, click Next. One last Next, and the converter is off and running.