Hello there, I want to know if this can be safely done or what I should do (for a WINDOWS machine);

I would like to upgrade to iOS5 & Jailbreak & Unlock using a PC for a 3GS with 359.3bootrom and 05.11.07 baseband and locked on AT&T itunes screen currently with iOS3.

Can I use a PC?

Is it true that my jailbreak will be untethered because of old bootrom?

Can I unlock on iOS5?

Do i need to create a custom ipsw?

What tools should I use?

To be safe, should i use tinyumbrella? what should i do with tinyumbrella in my situation?

any help would be greatly appreciated - i will report back here to help others on my experience.