Checkout this article because in this article you will find different Windows 7 Key which are totally free. So check it out and use this free keys for activation of your Windows 7. If you need any other keys you can still get them. Simply ask in the comment and I will definitely share it with you.
WINDOWS 7 PROFESSIONAL PRODUCT KEY
74T2M-DKDBC-788W3-H689G-6P6GT
2666Q-HGXKH-DFP6M-7YGBB-BG7Q7
22MFQ-HDH7V-RBV79-QMVK9-PTMXQ
2Q4QP-8P4MD-47YBP-7TXX9-FKDRM
WINDOWS 7 ULTIMATE PRODUCT KEY
RHPQ2-RMFJH-74XYM-BH4JX-XM76F
GMY2P-RBX7P-TQGX8-C8B9B-BGXFF
PTTCH-H7J6M-4XXWH-86RT3-66P6M
342DG-6YJR8-X92GV-V7DCV-P4K27
FJGCP-4DFJD-GJY49-VJBQ7-HYRR2
BPVVG-7KVMM-HGRZ1-SQZ4L-USRHM
HXJC9-DYFJ8-4R2TV-2X4FK-Y2JBH
WINDOWS 7 ULTIMATE PRODUCT KEY 32 BIT
MVBCQ-B3VPW-CT369-VM9TB-YFGBP
GMY2P-RBX7P-TQGX8-C8B9B-BGXFF
WINDOWS 7 HOME PREMIUM PRODUCT KEY
Q8JXJ-8HDJR-X4PXM-PW99R-KTJ3H
PPBK3-M92CH-MRR9X-34Y9P-7CH2F
WINDOWS 7 ULTIMATE PRODUCT KEY 64 BIT
C43GM-DWWV8-V6MGY-G834Y-Y8QH3
Q3VMJ-TMJ3M-99RF9-CVPJ3-Q7VF3
GPRG6-H3WBB-WJK6G-XX2C7-QGWQ9
9JBBV-7Q7P7-CTDB7-KYBKG-X8HHC
P72QK-2Y3B8-YDHDV-29DQB-QKWWM
Hope you got your key. Share these keys as much as you can.