I am using a recently updated iPhone 4s 5.0.1 and this is how I jailbroke it using Absinthe on Windows 7.
Prerequisites
This is fairly simple
- Install iTunes
- Make sure your iPhone is updated to 5.0.1
- Run Absinthe as administrator
- Select Jailbreak
- Wait a couple of minutes for the program to finish its work (The iPhone will restart, be patient)
- Tap on the Absinthe icon that has appeared on the home screen of your iPhone device
That is it, your iPhone reboots with cydia installed