Ok this is how it happened

I removed my hard disk for coping some data from my friends PC
without any problem it all goes and when I attached my harddisk back
Its still working fine exceept my CD-rom
I am using samsung CD-rom 52 X

It takes in the cd but dont read it

Can anyone help!!

Here is one possibility - characteristics determining the relationships of your drives to your machine and one another may have been changed in some way during the time your HDD was out of your machine.

This might happen in several ways -

If you turned on your machine during the time the HDD was out of it, the BIOS might have detected the absence of the drive and changed the logical settings of the remaining drive, which would be your CD-ROM. So you'd need to make sure they were put back in the proper relationship to one another.

Or, you might have had to change a jumper setting on your drive to get it to work on your friend's machine, and then forgotten to change it back.

One setting which may be affected by these things is the "master/slave" setting. Depending on the age and type of machine and the drive, these settings may be set in different ways - cable select, jumpers, logical (software) assignment are some.

Maybe the media? check for debris or scratches on disc and try another disc.

Also, make sure CDROM is being detected properly:
system properties ...hardware device manager...CD/DVDROM drives
(No exclamation marks)

Recheck connections..in case something came loose as well.

This is to complicated. My CD-ROM was identified by my PC but even when inserting a CD or DVD it did not work, I solved this by simply cleaning the lens with a Lens CLeaning CD or with a piece of cotton and some alcohol.

dear folks . . . . my LITEON 5236K & 1633 will not spin inorder to find the DVD file directory on my PC. anyone help!

Make sure the ribbon cable to your cd rom is connected properly, has happened me a few times, the power cable powers the drive to open but the ribbon cable goes from drive to pc

Nick