Pendrive distro

I'm looking for a solid Distro to fulfill three needs:

1. Fit on 16gb usb.( Ideally, 16gbs, but exceptions can be made.)

2. im in the process of learning Linux so I'd appreciate as much similarity to Windows 7 as possible.

3. A decent bit of available programs.

im going to try using it as a portable way to always have a working OS when using other people's computers. I'd also appreciate a Distro that isnt too taxing on hardware. Much obliged.


Basically any of them

There are differences between distros that have live environments (Ubuntu, Fedora, Debian) and distros specifically built to run in live environments (KNOPPIX, Slax, PuppyLinux), it all depends on what you require.

I'm looking for something that works well only being run once in a while. Probably something in the sub 10gb range with a gui. I hope that explains it, excuse my ignorance, I'm just getting into Linux.

If you're new to Linux I'd probably recommend Ubuntu, with a persistence partition.  As a general rule it's the most well supported and user-friendly.  You should probably try out several distros tho, just to see what you like.  I think there are even ways to install multiple live distros on one drive, but I'm not sure on that.

Linux Mint 17 with the cinnamon desktop is the most windows7esque in appearance that I can think of. Try as many flavors as you can though, they're all interesting and excel at different things or take a different approach. 

Well pretty much all distros are smaller than 10gb

LXLE has a good combo of lightweight vs features.

Puppy is super light weight 

KNOPPIX has a bunch of software but a bit heavier

Kali nice live distro used for penetration testing.

I think all distros with live environments would qualify for your sub-10G range. The largest of them all is KNOPPIX (4GB), which contains several desktop environments. Go with what others suggested and try out any distro you like with persistence if you want to save a few things.