There are several things involved in this.
1. Drive is not detected in BIOS.
If this is what your issue is? try verifying the jumpers. you can get info in the manual with the drive. Make the drive which you connect in middle of the cable to Cable-Select. you should see CS/CSL/CLS at the back of your drive.
Once the drive is detected in the BIOS then it shud show up in My Computer of the OS. If OS is unable to find your
2. Drive not detected in My Computer but is detected in BIOS.
Use this article ONLY if you are using Windows XP.
Goto registry editor and then locate the following key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318}
Delete "Upperfilters" and "Lowerfilters" on the right side.
Note: Sometimes you may find either of the keys or both. delete all which ever you find.
modifying registry can be fatal. be careful when trying the solution.
*support.microsoft.com/default.aspx?scid=kb;en-us;314060