Completly removing Jailbreak

[plattsy50]

I recently bought a PAYG Jailbroken iphone off a friend and it is currently running on 2.1...i dont use all that many apps to want it jailbroken so i just wanna remove it and use it for how it was intended and safely updated to 3.0..few questions about doing that tho..

1) How do I do it completly? I have heard you just click restore in itunes but my phone was jailbroken and updated using a different PC to mine, will that make a difference?

2) I have also heard you just connect to itunes and click update to 3.0 - this will remove Jailbreak.

3) Which of the above is correct way to do it!! I have read sooo many different ways to remove Jailbreak im afraid to do it in fear of bricking it up

and finally 4) Will my iphone definatly be clear of any jailbreaking? will it be back to being a standard Iphone and can i then update to 3.1 and any future updates?

I am using PC Vista if it makes any difference.

Any help is much appreciated.

 

[crunkcrumpet]

Plug your phone in and click sync (make sure all your contacts, calenders, and whatever else sync with whatever app you want). Then just hit restore, and 3.0 will install and all traces of the jailbreak will be gone. When asked if you want to set up as a new phone or restore from backup, it's usually best to start fresh because then we can be sure all files from the jailbreak are gone. The only problem with this is that you will have to load all of your contacts back on from wherever they are stored (Outlook etc) via iTunes, but all you have to do is tick a box.