The WEI is completely useless for u to determine a performance of your PC.
Ever wonder how a PC you own—or want to buy—stacks up against others? The Windows Experience Index is one way to find out.
This feature, updated for Windows 7, rates the performance of key hardware components such as the CPU, disk drive, and graphics card. The PC is then given a score between 1.0 and 7.9.
When you're shopping for a new PC, the Windows Experience Index can help you find the model that suits your needs. Scoring a PC you already own can help pinpoint slower components worth upgrading. A PC with a score of 2 is typically sufficient for basic tasks like word processing or web browsing. Running the Aero desktop experience requires at least a 3, while graphics–intensive software frequently requires a 4 or higher.