One thing that has come up numerous times for me while jailbreaking iDevices is to make sure the device can be jailbroken and unlocked. There is a simple little application from iH8sn0w called f0recast that I recommend running before you attempt to jailbreak your iPhone. Use the information below to download and run f0recast on Windows 7.
A few months ago I made my laptop a dual boot install with Windows & and Ubuntu 10.04. I recently remembered why I dislike dual booting and decided to remove the ubuntu partition. I never use it. When I need Linux I either boot a Virtual Machine or else I ssh to one of my many Linux servers, there is just no good reason to have a dual boot linux system for me. The laptop was booting from Grub so if I would have just deleted the Linux partitions I would have been left with a unbootable system, so I had to rebuild the Windows & boot loader first.
Below I outline my steps for doing so: