It should be ok without it. You'll just have to use 2 partitions.
For the 30GB problem, look on the back of the drive. You should see where the IDE cable goes in, and where the power cable goes in. Between them is another set of 8-10 pins. 2 of those pins at least should have a jumper (a little piece of plastic that bridges the gap between the pins) on them.
If there are 2 jumpers, read the documentation that came with the HD and remove the one that limits the drive's capacity. If there's only one, just pull it of and have fun
The reason they have these jumpers is for backwards compatability with legacy BIOS's. Sometimes if you have an older BIOS, it won't recognize a drive that's above 30GB.