Windows XP Unsuccessful on Start Up

When I turn on my Acer 3000 laptop, I get a black screen that reads:

... Windows did not start successfully. A recent hardware or software change my have caused this...

and then it asks me to restart in safe mode, last known good configuration or start normally. NONE of these options work. The computer just keeps restarting itself and coming to the same black screen.

I pulled the restore disks that came with my computer and started to reinstall all my stuff, but - see, at some point my cd-rom drive STOPPED reading data disks, so I had to buy an external cd-rom drive. I insert the first disk into the external CD - rom and it reads fine, but when I'm prompted to install the next one, it wants to read from my laptop cd-rom drive NOT the external one.

Ugh.

So - I have a copy of Windows XP, figured maybe I could just reinstall (repair) with that. I put the disk in the external CD-rom and all seems to work fine UNTIL I get an error code "0-000007b" or something like that which (upon investigation) is a boot drive error.

I have been told I might need a new hard drive, emphasis on MIGHT, and if I get one, how the heck will I install WinXP on it if I get a boot drive error? Will replacing the hard drive eliminate the boot drive error?

What if I just replace the internal CD-rom drive, so I can reinstall the disks right from the laptop as opposed to the external drive which doesn't seem to be working???

What if I just toss the computer altogether? ;)