Much thanks in advance for any help you guys can give.

So here's the issue: I'm trying to learn to mine LTC/altcoins (never really delved into mining, but I spent some time a year ago or so trading BTC, decided I wanted to learn more aspects of cryptocurrencies). I've acquired a friend's old gaming PC for the job, and heres what I've got, that I know of:

AMD Radeon 6800-series (I was told it's a 6870 - is there any way to check between -50 or -70 without prying open the case?)
Windows 7 32-bit
cgminer 3.7.2
Catalyst driver 12.8
SDK 2.5

I got the rig running on a basic setup before I messed with the drivers. There was no SDK and I believe the Catalyst was 14.1 or maybe upper 13.x's. Computer ran super slow and I made like $1USD in a week. Not exactly ideal.

I've spent all day googling, reading forums, etc, and I've cleared off all the Catalyst software using ATIman Uninstaller. Did a clean install of 12.8 and SDK 2.5, and my basic .bat file runs, but in cgminer I get the error:

"Error -1001: clGetPlatformIDs failed "

Followed by

"clDevicesNum returned error, no GPUs usable"

My basic .bat file (which worked before) is:

setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
cgminer --scrypt -I 19 --thread-concurrency 6720 -o stratum+tcp://us-east.multipool.us:7777 - u thetedderbear.tedbear1 -p x

What am I doing wrong?

After much googling, I'm unsure if I'm using the right driver, if I have the wrong SDK, or if I even need the SDK?

I'm very much a noob to mining, and a noob to coding and delving deep into computer systems in general. Any help is greatly appreciated, and please be detailed, so I know what you're talking about lol.

Thanks guys!