I forced my pc to shutdown by holding the power button. I tried to open my pc after that but shows complete black screen. After that I remove my computer cover and discconected everything and connected it again. Now the computer starts but harddisk wont detect. I tried every thing. Changing the ide cables too. still wont detect.I hope u can understand what i am trying to say cox I dont no computer terms. After trying everything I connected cd rom ide cable to harddisk it detects fine. since harddisk is fine again i tried connecting the harddisk ide cable it wont detect. I even changed the cables 2 to 3 different cable. the I changed the cdrom ide cable on mother to harddisk cable. now it won detect. but when change mother cdrom ide cable to cd rom harddisk detect. Cud it be possible that my mother board harddisk connecting place doesn't work anymore and i have to change mother board.

Yes, it is possible that the IDE connector on the motherboard is damaged. However, it might just be a jumper setting problem.

From what you have said, I understand that you have one hard disk and one CD or DVD drive. No others. Is that correct?

I also understand that the hard disk is connected to one IDE cable in the Primary or IDE1 connector on the motherboard. The other end of the cable should be connected to the hard disk. If the cable has 3 connectors, do not use the one in the middle.

Ensure that the jumper setting on the hard disk is set to the Master setting and not the Cable Select setting.

I understand that the CD or DVD drive is connected to a second IDE cable connected to the Secondary or IDE2 port on the motherboard. This should have no impact on the hard disk. Howver, during this test, disconnect the second cable so that the CD or DVD drive is not detected.

Check that the hard disk works during this process. Then, re-connect the CD or DVD drive in the same way as the hard disk - use the second cable in the Secondary IDE port on the motherboard, connect the other end (not the middle connector) to the CD or DVD drive and ensure that the CD or DVD drive's jumper setting is set to Master.

Then it should all be fine.

Let us know how you get on

jumpers settings are correct I and someothers also checked it. the cable i have two connecters. master and slave cable select. Seems like u said my primary ide is damaged. Can I make the motherboard work by using sata adapter and connecting sata harddisk.

Yes, if you get a PCI SATA controller card (or if your motherboard has SATA ports as well as IDE ports), then that would work from a completely separate controller so that should be OK. If you get a PCI SATA controller card, make sure that it is a bootable card, i.e. it allows you to run your main hard disk with Windows from it rather than only being able to control a secondary hard disk.

Incidentally, when you said that the hard disk wouldn't detect, I assumed that you meant that you were checking in the BIOS (System Setup) screen and the BIOS wasn't detecting the hard disk. Is that correct? If you haven't been into the BIOS yet, you need to check in there that the system is actually looking for devices such as hard disks on the Primary IDE ports.