I just bought a toshiba laptop with windows xp. I have desktop internet service through comcast but can’t seem connect wirelessly in my home. Any suggestions?

I’ve been looking around to see how to do it, and I’ve been hearing that I need to partition everything on my current hard drive/os, and that I need to do a bunch of random stuff to register windows 7. I’ve just been wondering if it can be easier.
Can I just take out my current hard drive, put in my new one, load the W7 disc, and follow the installation instructions?
Or does it have to be more complicated?

I have an “ISO” of Windows Vista I made using magic iso. I was wondering if there was a way to install it on a usb then boot it on your laptop?

My grandmother has a gateway windows XP computer and some how everything got deleted, all files, hard drives, and everything. We want to download windows xp off of my computer onto a disk and install it onto hers. How do I do this? I have blank disk and stuff, I just need somewhere on the internet I can download windows xp for her computer. Please Help!