Weather Microsoft is watching your system. Don’t they have any other work than that. “wpa.dbl “.WPA stands for Windows Product Activation for Windows XP and above version of Microsoft OS is using the wpa.dbl file to activate the product. There are lot of rumours that, by using this file Microsoft is going to watch your activities. Ya its may be true but not all your personal activities ,it will check for the OS license only . Ok how MS is going to check the license, weather they are going to take my H/W info. Yes they are, there are few listed H/W which they are going to check they are

NIC & MAC address
HDD Serial Number
processor number
Display Adapter
SCSI Adapter
IDE Adapter (effectively the motherboard)
RAM Amount Range (i.e., 0-64mb, 64-128mb, etc.)
Processor Type
CD-ROM / CD-RW / DVD-ROM

The “wpa.dbl “ is going to have the info of the above said H/W. Then What its does? Every time you boot you system the OS will check the H/W serial number with the number in the “wpa.dbl “ file, if your version of OS pass 7 checks then only your OS will be considered as licensed one. If else you can all MS through phone and you can activate it

What happen when I change the H/W?
If you change 1 or 2 H/W there is no problem if the OS passes less then 7 checks then you want to reactivate your OS through phone call. So this what “wpa.dbl “file is going to do in your system