Honestly the manual that came with it explains this pretty well if you actually read it. I know nobody reads manuals but for once it's worth flipping through. The troubleshooting section in the back covers the most common problems.

I learned the hard way to always back up before messing with this kind of thing. Burn a CD-R of anything important first. It takes 10 minutes and could save you from losing everything if something goes sideways.

I work in IT and see this question a lot. The short answer is yes, it's worth doing. The long answer depends on your specific setup. What operating system are you running? That makes a big difference in the approach.

I dealt with this same issue last year. The key thing is to make sure you're using the latest version of your software and check forums like Slashdot or Ars Technica for specific fixes. Technology changes so fast that advice from even 6 months ago can be outdated.

First thing I'd do is reboot and try again. Sounds dumb but you'd be amazed how many 'tech problems' fix themselves with a restart. If that doesn't work, write down the EXACT error message and search for it — somebody on Experts-Exchange or a Geocities help page has hit the same thing.