HDD Upgrade, OS Upgrade, Original Restore intact, F12 Choice

what I'm trying to do is use a 250 gig sata drive in my aspire one. ideally the computer will boot to windows vista and I would like to be able to use f12 at boot to load XP occasionally. Also, the ideal end result will leave my factory 120 gig aspire one hard drive in the same condition that its in now so that if by some chance the 250 gig drive loaded with vista and XP crashes or I decide to sell the machine at a later point in time I can just swap the hard drives back.

I have no problem opening up the machine and swapping the drives (I've already done this at one point just to see how vista operated on the aspire one but since then I have switched the drive back to the factory 120 gig because sadly my vista activation was going to expire in three days)

here's a list of tools that I can work with.

250 gig sata drive
120 gig sata drive (original aspire one drive which is currently in the acer one at the moment)
sata to usb adapter
gateway laptop with vista (this has a dvd drive)
vista install cd
I do not have a cd/dvd of XP so I will need to use the XP that is currently on the original aspire one drive (recovery files) to deploy XP onto the new drive.

a step by step would be great. being that I don't even know how I would use the recovery in the aspire one to simply swap the hard drive for the larger one and restore back to factory XP. kind of dumb that they don't give any options for recovery in the event of a bad hard drive or in my case a hard drive swap.

 

mcmism...

FIRST make a Repair/Install Boot disk/USB stick (2GiB smallest) using Windows

If you have/get an external 2&1/22 Hard drive case... to put your 250 GiB HDD in (and a 2 USB to Mini USB Cable) THIS one comes with the cable
http://www.ebuyer.com/482877-extra-value-2-5-black-hdd-enclosure-usb-2-0-gd25640
Using (Free) Mini Tool Partition Magic copy the essential PARTITIONS to the larger drive - http://partitionwizard.com/free-partition-manager.html

Remove 250 Gib HDD from external,
Fit in Computer,,

Boot from the Repair/Install media and allow the Repair to locate your Windows system. if it doesn't find it after the first 'go' follow this How to...
http://www.howtogeek.com/howto/32523/how-to-manually-repair-windows-7-boot-loader-problems/

Hope this was useful