first thing you need to do is go to the computer manufacturers website and see if their are win7 drivers for your specific computer model. If not, then DO NOT upgrade. You will be asking for problems.
One other thing, before you start the process, make sure you have backups of any files you cannot afford to lose. Also make sure you have an upgrade version of win7 not oem. You could be asking for problems later if you do not have a legal upgrade
To install is easy, if your computer is compatible with win7.
1. Place the win7 into the drive while the computer is running. It should auto start. It will check your system to see if the xp is legal and activated.
2. when the computer reboots, you need to make sure the boot order is correct. cannot tell you what key to press since computer models are different. One of the very first screens should say something about pressing a key to enter setup.
3. once the install starts, just follow the onscreen instructionsl
4. manually update windows and your drivers. this will take take an hour or two of downloading and rebooting.