cd drives not working on dell c840

I'm having a real puzzling problem ... after removing the mother board of my dell c840 to fix a loose ac adapter jack (which was repaired successfully) now after windows xp starts i noticed that neither the opitcal drive a toshiba sdr2102 cdrw/dvd rom drive or the expansion bay cd rom drive a samsung sn-124 drive are working at all.. the are listed in the device manager with a yellow warning flag.. the driver details says error 39 the drivers cant be loaded.... i have tried removing/uninstalling the drives and rebooting ...... but still same problem remains.... the drives do not show up on the my computer listing either....
any suggestions on what to do next??

 

Something else to add about this... the driver details are the driver files are made up of these 4 files.... cdrom.sys, imapi.sys, redbook.sys those 3 are in the system32\drivers folder of windows.... the 4th one is in the system32 folder and is.... storprop.dll ..I moved the files to another temp folder to see if restart would rewrite them.. the 3 sys. files were rewritten but the dll file wasn't so i put the files back in place and restart still no improvement...I have read some previous threads about something similar and there was talk of the problem being with the registry... i haven't done any editing of the registry before and i didn't want to try that yet...

 

I found a post that had the same problem with a fix of editing the registry..
this post by Jerry K on 3-10-2007.....

>Situation
>There is a yellow exclamation mark for CD/DVD drives in Device Manager. >The device status in the properties of the driver might indicate an error >code, for example 32, 37, or 39.

>Solution

>To solve the issue, you have to edit the Windows Registry:
>Click Start, then Run, type REGEDT32 and click OK.
>Locate and then remove the following registry values:

>HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlCl >***{4D36E965->E325-11CE-BFC1-08002BE10318}LowerFilters

>HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlCl ***{4D36E965->E325-11CE-BFC1-08002BE10318}UpperFilters



>Close Registry Editor.
>Reboot the system for the changes to take effect.

>Note: Some programs are unable to detect the CD/DVD drive after these >steps. To solve this, simply re-install the program in question, eg: usually >your recording software. Also, in few instances the order in which the >programs are (re-)installed can make a difference.

I did this fix and yes it worked.. problem solved.. thank you Jerry K