Installing Cydia
If 4.02 or up firmware,
Attach your iPhone / iPad to your PC or Mac via your USB cable first.
From Your PC or Mac Run:
Run the latest http://www.limera1n.com
Another Way To Install Cydia if for some reason the above did not work:
REDSN0W 0.9.6b4 for Mac: http://www.iphone-storage.de/redsn0w_mac_0.9.6b4.zip | (Video Instructions )
REDSN0W 0.9.6b4 for Windows: http://cdn.nspwn.com/redsn0w_win_0.9.6b4.zip | (Video Instructions )
If this worked, continue to FLASH or TETHERING INSTALL