Update: I have just found out that the keys you get using this method are not unique. You will only get 5 unique keys for 32-bit version of Windows 7 and 5 unique for 64-bit version. Following are the keys that you will get using this method. They will work fine so just use them!
Windows 7 Keys for 32-Bit version:
6JKV2-QPB8H-RQ893-FW7TM-PBJ73
QXV7B-K78W2-QGPR6-9FWH9-KGMM7
GG4MQ-MGK72-HVXFW-KHCRF-KW6KY
4HJRK-X6Q28-HWRFY-WDYHJ-K8HDH
TQ32R-WFBDM-GFHD2-QGVMH-3P9GC
Windows 7 Keys for 64-bit version:
482XP-6J9WR-4JXT3-VBPP6-FQF4M
7XRCQ-RPY28-YY9P8-R6HD8-84GH3
D9RHV-JG8XC-C77H2-3YF6D-RYRJ9
JYDV8-H8VXG-74RPT-6BJPB-X42V4
RFFTV-J6K7W-MHBQJ-XYMMJ-Q8DCH
