Cannot seem to play dvds or cds on dell inspiron 2200

There are three possible reasons for this, the first one is that, your CD/DVD lens might have become weak, and therefore might need to be changed, or if its just dirty, you might just need a lens cleaner.
The second reason is that, it might be that the CD you are trying to read is bad, dirty, or not properly burnt...in this case, you might need to clean the surface of the CD properly then re-insert it.
The third reason is that, your CD/DVD Drive might be having a conflict within the OS. What I would suggest in this case is that, Power up your system, then when the system boots, just right click on my computer, then properties, then select the hardwares tab, then click on device manager.
When you get to device manager page, try and locate DVD/CDrom Drives, then click on it, if your drive is there, then just right-click on it, and select uninstall, and after this, on that same page, click on 'Actions', and select "Scan for hardware changes". But if its not there. Just click on the "Actions, and Then select "Scan for hardware changes".
This should automatically place your CD/DVD drive back inside your My Computer page. After this, try the CD or DVD again.
Hope this helps you out.
Goodluck!