Please help! My WD 500gb Sata Hard drive is not detected by my computer!

[Limpingb41t]

Hello members. My internal WD hardware is not detected by my computer. When I boot my computer,it loads and asks me "Insert disk to boot from CD" and it hangs. And I went to bios too and it did not detect it either.
Things I have tried:
(0)Checked whether it is plugged in correctly.
(1)Connected the hard drive to another computer and it only worked once.After I restarted it the Hard drive is not detected and my OS dose not load.
Why I believe that it is not a problem of my original computer?
I plugged in another Hard drive and it worked unlike the WD hardware.
Why I believe that the WD hard drive is not dead?
Because it worked on my other computer which had an OS installed but as I said, after I restarted, the my computer dose not load unless I unplug the WD hard drive and reboot again.

Please help me fix this problem and it would be really appreciative and I need to fix the problem Urgently because I have 430GB of programs and documents in it.

PS: I am looking for a mentor.

[Salmon Trout]

I don't think we do mentors on here.

You cannot take an OS disk from one computer and boot it in another.

[Limpingb41t]

I see. So is there a way to fix it? I want it to work on its original computer(accer).
Edit:The OS was on my WD hard disk because it was the Main disk. I have used it for 3 months and all this happened just when I restarted the computer.

[Computer_Commando]

If BIOS doesn't detect it, either the data/power cables are bad or not making a good connection, or the drive is/has failed.

[Limpingb41t]

If BIOS doesn't detect it, either the data/power cables are bad or not making a good connection, or the drive is/has failed.

Then why dose my computer detect other HARD DRIVES? And why dose my "/has failed" hard drive work on my other computer?
Thanks for reply dude.

[JJ 3000]

data/power cables

[Limpingb41t]

I went to bios and set the priority to hard disk at cmos. Now the hard drive is detected and it loads but another problem encounters: It dose not start os(windows 7) and it hangs at "starting windows" logo area. Please help!

[lostcoast]

you loaded xp after win7 corrupting the boot....now install xp then win7 or fix the boot config..and no I cant help with it.  good luck

[Limpingb41t]

you loaded xp after win7 corrupting the boot....now install xp then win7 or fix the boot config..and no I cant help with it.  good luck

Its ok. Thanks for replying. I couldnt install windows xp. It has only reached 24%now. And it was started since yestarday. Now more than 24 hours and only this much. I suppose that I will just forget about it and move on.