BleepingComputer.com: Toshiba A305 Recovery Disc With New Hard Drive

I have a Toshiba A305 laptop. It stopped working properly with a "no bootable disk" error. Also when we went to try and recover the computer, it said there was no hard drive. We found the recover disc DVD and tried to run that, which worked for a couple of minutes, but eventually stopped with error 05-0172-045D. So, I assume this is a bad hard drive. I assume I need to replace the hard drive.
1. Is the problem the hard drive or might it be bios or something else? Is this series Toshiba known for hard drive problems?
2. Can I replace this with a 7200 RPM drive vs the current 320gb 5400 RPM drive? How do I find a specific drive that will work with this laptop?
3. Can I use the Toshiba recovery media DVD for the Satellite A300 Series, Windows Vista Home Premium 64-bit SP1 to restart my computer? IE, I just put in the new hard drive, pop the DVD into the reader, and everything will work fine from that point on with the new hard drive being put into the original Toshiba out of the box condition with proper partitions, Vista Home Premium, etc?
4. Or is this much more complicated and I need to take it to a shop and pay $250 or so--or buy a new laptop?

This post has been edited by hamluis: 04 December 2011 - 12:28 PM
Reason for edit: Moved from System Building to Internal Hardware.