[Chriszuma]

Yeah, my team just acquired a new(er) laptop, and I was having similar problems, except that when the progress bar got partway across (there was no pattern to how far it got) it would just stop dead in its tracks. I fiddled with every setting possible in the device manager, and eventually came to the conclusion that the computer is a little f'd up. We got a usb-serial adapter and that works well enough. My suggestion: go to device manager and make sure your COM port is operating, and then just fiddle with every setting you can find. If that fails, try a new serial PCI card (if it's a desktop) or a usb-serial adapter (if it's a laptop).
EDIT: Oh yeah, and see if there's a BIOS update for your computer, sometimes the manufacturers figure these issues out and fix them for you.