Time Machine BackUp on external drive

First of all a big Thank You to everyone in mac-forms - for all your input, it is greatly appreciated.

FIRST OF ALL SOME BACKGROUND BEFORE THE QUESTION:
~I have a 13" MacBook Pro with a 750GB harddrive, with 500+ Gb of data on it. Just before I traveled to Europe, I did a TimeMachine back up.
~ I am Europe now and want to give my Mac to a friend, with the idea of buying a MacBook Air when I get home.
~I also have an 8 year old 15" Mac Book pro at home with a 300GB hard drive with a lot of completely different data than what is on the 13" . It will be a few months before I can buy the new AirMac. So my question is ....

QUESTION 1
With my old 15" macbook running as normal, can I install my current TIME MACHINE backup for the 13" mac on a properly formatted external hard drive, and then will it run like a normal computer so I can access my data that was on the 13" --until I get my new AirMac
Question 2:
If it is possible to run a mac from an external hard drive with the 'main/original/internal' hard drive still in in operation - i.e. is there a way to switch back and forth between the two hard drives(the internal one and the external one) and operate each one separately?

I am here in Europe for only a week and need to know before I leave so I can decide if I can give my friend my 11"

Thanks for your help (and please don't be too tough on me for what may see to de a dumb question)

Soper777
OS X Mountain Lion (10.8.3) running on both 13' and 15'

While I have never done this, I have recovered a time machine back-up and I believe you would have to install the operating system onto the external drive after formatting and all that jazz. Then, to run each independently you would only have to tell the computer which one to boot from. The time machine back-up could also just be used; you won't be able to boot from the time machine back-up drive but you can search the files and use them.

I think the easiest way is to simply install the operating system on an external drive and then boot from it when you want to access the data on it. If you chose this route, whether you boot from the external or internal, the other drive will still be available for search and use on the computer. If you boot from the internal, the external will show up like any other, and if you boot from the external, your internal is available through finder.

Hope that helps!

PS: You need at least a snow leopard disc to begin the process... you will then have to install the newest operating system or the one you were using with the back-ups. This is probably the most annoying part. I didn't have a disc the last time I wanted to do this so I had to go to the Apple store and buy a snow leopard disc and then upgrade to the next one and then upgraded to mountain lion after all of that. It is a shame they don't offer a mountain lion disc for installation. The reason you need to do it that way is you need the app store in order to get mountain lion which wasn't available until snow leopard or the one after. If you have already purchased mountain lion, I believe you can install it on multiple discs using your Apple ID.

PPS: I just read through this and does it make sense? If not, my bad.

Time Machine BackUp on external drive - in the OS X

Thanks Flavacraze,

I understood what you said, but have one question -- I have my Snow leopard disc. I can't remember if I have a Lion Disk or not - I think I just paid for it and downloaded it.

Will I have to buy a Lion Disk to do this, or can I just go from Leopard to Mountain Lion - that's the only question I have.

It occurred to me as I read your response - that once I have a Thunder Bolt, 2 TB hard drive configured this way -- when I am hopping around the globe -- That when ever I plug into someone's mac (and almost all my friend have them) I am carrying around a big computer in a very small case.

Thanks again

There is no such thing as a Mountain Lion disc! You can only get it through the app store, but since you have already purchased it you should be fine.
And as far as the last part of your response, you are exactly correct but you are carrying a 2 tb hard drive, not the computer... you will still be limited to the speeds of whatever computer you are plugging into. But you are correct... I use a 250GB external as a boot disk in case any one of the many computers I interact with does something fishy. I just plug it into the computer in question, boot from it, and then I can mess with the internal hard drive and what not from the faulty comp.
Good Luck!

Thanks again -

Another question --
will the external hard drive all formatted like we spoke of, that I can boot-up from on a mac, -- will it also boot up on a Microsoft computer.

Sorry for being a pest on this little thing.

soper777

Sorry I just noticed that you asked a follow-up question (7 months later... sorry).
It shouldn't work... You have to jump through hoops to get Mac OSx to boot on a Windows PC...
I've never done it myself but I hear it is a pain in ****.

Sorry for the delay... If you were able to, let me know.

It doesn't matter anyway.... because we do not talk about installing or booting OS X from a Windows computer. That's known as a Hackintosh which is off topic in our forums. I'm going to close this thread in case the OP responds for more information.