Comp won't read CDs

Hi I have a Fujitsu Siemens computer which is running fine except suddenly it won't read data that I've recorded onto CDs. If I put in a pre recorded shop bought CD it opens it up fine but if I put in a CD that contains data or photos I've saved nothing happens. When I click 'my computer' icon and then the CD Rom drive it opens up as empty even though there's a full CD in the drive, yet if I put in another pre recorded CD it shows up. Also, it won't let me burn CDs. It takes me through the process but at the end when the job should be complete I'm still left with a blank CD. Any suggestions? I'm not very technical so all responses need to be explained in idiot speak - thanks.

Try this; http://www.dougknox.com/xp/scripts_d...cd_dvd_fix.htm .It could be the drive has developed a fault and needs replacing. You could also try a lense cleaner.
Addition: this is a troubleshoot list from ms; http://support.microsoft.com/kb/324129/en-us