First of all I know nothing about the inside of a computer. So having said that. My laptop Dell Latitude D640, Windows XP Professional, says I have no disk to boot off of. I changed the bios to boot off the CD I got for my Operating System. Once all the info was loaded, it said to hit R for recovery (do not have a recovery disk) or hit continue. I hit continue and it still tells me I have no disk. This computer was refurbished and worked for 4 months and then I got an error message that said A disk read error occured. I was told to get a reinstallation CD and use it. I changed the bios, everything is fine until I get ready to reboot. Nothing. What am I doing wrong. Is it time to call in the calvary or throw it out. I hate it because not having the money to spend on a new one, I purchased a refurbished on. Please help me. Thanks,

It sounds kinda strange for this to happen all at once...
Have you had any issues reading / writing to the HDD before?
Have you noticed if the computer has been running really slow lately? How long have you had it?
Here's the problem... you don't have an HDD, either there is a loose cable, or it is corrupt.

Probably isn't the way you expected, but for what it's worth... welcome to Techspot!

I only used it for the internet. Did not save anything to it. Computer would freeze now and then but I thought it might be IE. I bought it refurbished April 27,2009.

Thanks.

Well, I'm sorry, but it looks like you'll have to purchase a new HDD. Maybe if you go to the store where you purchased it, they can make you an offer for a new HDD, but you'll be looking at spending $100 (depending where you live).
I wish you luck