Code 39 error CD/DVD

XP home on Toshiba laptop
suddenly CD/DVDis not recognized ran the usual driver check, uninstall - reinstall drive, ran a check on physical drive it was OK but nothing worked, got Code 39 error ran a check on MS for this they had a so called fix ran it but came up with no fix for this system. they desacribe it as something in the reg. upper & lower filters - finally I actually went into the reg and there is NO entry for upper/lower filters. even tried a working external DVD drive same result. (Code 39) MS claims it may be apps like Nero or Itunes but I've been running Nero & I tunes for 3 months with no problems on the CD. I did clear out some Trojans, could they be the cause? Tried running restore it failed 4 times
please help
thanks

 

did you follow the registry path exactly as described in the MS guide, you can have sometimes only one and not both upper and lower, but I would be surprised if there was none.

 

Don't discount those programs you mention. Often there is some sort of change and these problems occur.

 

code 39 error

yes i followed exact path, in fact i read out loud each letter & number.
there were no upper or lower filters, still got same error and no dvd even uninstalled i-tunes. no luck. very frustrating