Windows Vista Experience Index

The Windows Experience Index measures the capability of your computer's hardware and software configuration and expresses this measurement as a number called a "base score". A higher base score generally means that your computer will perform better and faster than a computer with a lower base score, especially when performing more advanced and resource-intensive tasks.

Please visit the following web link to obtain more information on Windows Experience Index:

http://windowshelp.microsoft.com/Windows/en-US/Help/f59082f4-6385-4a61-ba7e-2de9625a780a1033.mspx

Windows Vista Experience Index scores currently range from 1 to 5.9. Your computer is rated with an overall score, called the base score, and with sub-scores for each of five individual hardware components: processor, memory, graphics, gaming graphics, and primary hard disk. The base score is determined from the lowest of the five sub-scores, because your computer's performance is limited by its slowest or least-powerful hardware component.

Please visit the following web link which contains information on interpreting the base score:
http://windowshelp.microsoft.com/Windows/en-US/Help/0fee4637-8b21-41f1-87f6-66d2205420d61033.mspx

You can use a wide variety of different hardware components to create a PC with a perfect score of 5.9. The following web link describes some high rated hardware list to increase your base score:

http://windowshelp.microsoft.com/Windows/en-US/Help/60d9b045-e2fe-4f7a-9111-e2f2222851991033.mspx