Installing Second Hard Drive

DISCLAIMER: I am not a hardware guy, nor am I a sysadmin type. But I'm trying to do things on the cheap in the DIY spirit. A friend gave me some old hardware, and I'm using it to try and upgrade my old desktop. I had some misadventures last night trying to install a second IDE drive on my Dell Optiplex 270 (yes I know it's old, it's just a lab computer). The drive is a 40gb Seagate that I'm planning on using for TempDb. When I first put it in, I didn't change the jumper settings, so the pc thought I had two master IDE drives. This caused BIG problems in BIOS. I could no longer boot, and my computer no longer recognized my original master drive. I changed the jumper settings of the second drive and tried to reboot - no luck. Now the pc was reporting TWO unknown drives (which I suppose is progress). I played around with the BIOS settings, but again, no luck. Then today after googling the task, I came across this how-to article that explains that the IDE cable that connects the IDE drives to the motherboard must be plugged in to the drives in a very specific way. The instructions worked perfectly. When I booted up in Windows, I noticed that that drive had two partitions of 20gb each. Wanting to use the entire drive for my new TempDb, I researched how to delete the partitions and reformat.