I was using the dvd and then it suddenly stopped working and doesn't recognize when i put a dvd or cd in the drive

Most likely a problem with the reader on the CD/DVD Drive.

Very easy to swap out a different CD/DVD Drive. Add the new device and see if that resolves the issue.

Most DVD drives are also CD drives, and it sounds like the DVD part is broken, you need to replace the DVD drive, this is done simply by buying a new one, I recommend Newegg.com ( if your unsure search exactly what you already have) then opening your case (tower) and just unplugging old one and plugging new one in, it really is very doable for even a novice.

check to see that it is listed under MyComputer, if not, go to device manager and see if it is listed and working normally.
If so, the drive may be defective and will need replacing.
I hope this helped.
Good luck and have a great day.

If you are using Microsoft, have you tried using the driver search tool? When Windows says it does not recognize a drive via pop up, click it to have the option for windows to search for the drivers online. If that doesn't work, you can manually search for drivers, which can probably be found on Micro Solutions' website. If the PC cannot detect any drive at all, then odds are the installation was incorrectly done.

Does the tray open for you? Re-boot the computer and go into the BIOS and see if it is listed by the BIOS. Did you accidentally remove the hardware? Go into the control panel and add new hardware and see if it detects the drive and re-installs it. Otherwise the drive might have stopped working.

You may use any CD/DVD drive lens cleaner to clean the lens as it may be that the lens in the CD/DVD drive is not able to recognize the disc due to accumulation of dust. Next, you may perform System Restore to the time when the CD/DVD drive operated normally. If the issue persists then you may try reinstalling the Operating System.
If the issue persists even after performing all the above mentioned steps then the issue may be Hardware related and the CD/DVD drive may require service.

I found that there was a firmware conflict caused by the installation of iTUNES. I uninstalled and cleared the upper and lower filters in the registry and the internal DVD-Rom is recognized. First I cleared the registry and the drive was recognized after a hard boot. So Far no twitches. Knock on wood.

Hi RC2935
Try this and see if it will help you 
Here is what you do  Click on start and then go to run type in regedt32 For Vista Click start and search for regedt32 and click on it 
Go to the following HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318}  
Delete the upper and lower Filter or witch is available close window and restart the PC it will work  
This is common on the Acer, HP,Toshiba etc,etc  
if you need help let me know 
kind regards mervin

the blank media must be compatible with the burner drive that you're using... meaning if the drive is for CD-R you can only use CD-R blanks not CD+R. if the drive is CD-/+R then you can use either CD-R or CD+R

try a firmware update