Is it possible to take a gig or two of hard drive space (considering I have 257 gigs free, and plenty to waste) and convert it to RAM for the system to allow more programs/processes to run? I have problems with programs freezing up from time to time, and I'm figuring some more RAM would really help out. Can it be done?

No.

They store memory differently (most computers have a spinning HD, but all have a stationary RAM storage). So yeah, probably not. You'll have to buy external RAM or something.
PS: I really don't know, so please defer to any techie.

TL;DR: Ignore me.

Nevermind, I found out how. Virtual Memory, I can pretty much set the amount of ram I want. woopie, I have 3.5 GB of ram now.

increase your page file
But page file is not good as buying more ram.
If your ram is not at least ddr2 I would buy a new computer.

computer, click properties> advance system settings > performance settings> advance tab > virtual memory > put bigger number
(that is how to get to it on win7, it should be similar for w/e windows you are on)

Increasing page file space will not make your computer much faster, because your hard drive is thousands of times slower than RAM.

I'm in disbelief that in two posts no one even mentioned page file.

It's mostly useful when you have lots of background tasks that don't really need to actively read the RAM, they simply have it in case they need it quick in the future(wastes of space, basically).

If you have two hard drives, placing the page file(or swap file, on other OSes) on the hard drive that is least used, or the one with the fastest RPMs, if it's any significant difference, will help boost the speed of the virtual memory. And I certainly wouldn't recommend relying on using Virtual Memory for games or anything, it's only good for programs that don't require a fast read/write speed.

Also, many OSes have programs written for them, or built-in, that lets you use flash memory, a flash card, for example, as RAM, this is much faster than storing it on a hard drive, as flash is much faster at random access functions than a platter+spindle style hard drive.

http://www.downloadmoreram.com/
Why waste HDD space when you can just download some more ram?

but seriously, if you use less than half of your ram, increasing the virtual memory won't help. When you use the pagefile, your computer slows down to a halt. I turned my pagefile off on my laptop. The worst that happens is gimp closes when it gets too big. If you have 1 GB of RAM, your pagefile is already plenty big. (it's 1.5 GB unless you messed with it). If you have 512, you're going to want to increase it to 2 GB. If, for some god forsaken reason you still have 256 MB, 2 GB will also be fine. More ram can add to system stability of memory intensive programs, but you don't get any huge benefit if you don't use more than half your ram. The best idea is to close the BS programs. If you have more than 50 processes running at startup, you're terrible at computer.

It takes a few hundred cycles to access from RAM while about 10,000 are needed to access a disk HDD. SS drives are slightly better for this purpose, but really, just buy RAM; it's incredibly cheap.