Upgrading from Vista to Windows 7

So I inherited my brother-in-laws old laptop because he bought himself something newer. It currently has Vista on it. I would like to install Windows 7 on this laptop, and I have a legit key for Windows 7 Pro, however I can't find the CD that had the ISO on it. I got the key from a friend who worked at MS, and the ISO from a friend that *had* access to tech.net, but does not anymore.

Is it possible to just get the ISO and burn it to a DVD? If so, where can I get a legit copy of the ISO? Or, if it is possible to install it from a USB, how would I go about doing that?

Also, my brother-in-law had his language set to french. How can I, when upgrading to Windows 7, change the language to English?

Not that this will be much help, but I'd think a torrent of the ISO isn't necessarily the illegal part-- it's cracking the serial that is. So if you have a legit serial, then I'd think any ISO you get is technically "legit". Otherwise, I'm afraid I couldn't help much. I think installing from USB is a simple matter of copying the ISO to the USB stick then making sure USB is lsited as the first boot source, but I've honestly never done it myself.

Here are some links that used to work for the ISOs. From digital river, who distributes for MS.

What WipEout said. In terms of license, the disc doesn't really matter, it's just installation media. The main thing would be downloading it from a trustworthy source, the one MannishBoy linked is as good as it gets.

Use this tool to put the install disc content onto a usb stick.

After that, as long as you've got the 25 digits for a valid key which aren't expired or tied against another bit of hardware, etc, you should be good to go.