switch on some OS in a removable disk

I'm still not sure what the OP wants or has done.
It is time for more coffee.

Glad I`m not the only one.

I think OP wants to install either w7 or 8 or XP to an external USB attached HDD and boot it up.

Well my two bobs worth I would have liked to seen some system specs like I asked for first up as we do not know what exactly we are dealing with here.

Even a list of components parts would be good
ie Computer with internal HDD
two x ext HDD
three x sticks
four x retail OS's - what??

Seems we are going around the houses looking for the right address with no number or street name

hesam said:

Now what do you recommend؟

Uhmm, for a start....

To better help us to help you would you please add your systems specs? Here's the correct way to do it. :SystemInfo See Your System Specs Under System Manufacturer/Model Number add whether it is a desktop or laptop and whether self built. Very important

Log in to Seven Forums and you will be able to transfer the info directly to the specs page in your profile from within the System Info app.

After doing this your specs will be available in each of your posts.
Click on My system Specs in the lower left of this post to see how it should look.:)
Full instructions are in the tutorial.

alphanumeric said:

hesam said:

Now what do you recommend؟

I'm still not sure I know what you are trying to do? We need more details and a better explanation of what it is your trying to do.

Well I did ask for system specs up front alpha but either it's been given away or there is a fair bit of confusion going on somewhere in the world.