How are you determining that the drive isn't detected?  When you install a hard drive the first place to look is the setup.  Enter this by tapping the F2 key as the computer first starts up and examine the screens for menu entries relating to the hard drive.  If the drive is properly detected you should see the size and possibly the model number of the drive.  If setup doesn't have an entry for the drive, or the size is incorrect, such as a number around 32 GB, you need to check the drive for proper placement of the jumper.  There should normally be only one and it should be placed for Cable Select.  Once you have the drive properly displayed in setup you can try booting from the installation disk for your operating system and following the installation procedure.

 

The Dimension 3000 should be able to support large drives so I don't think the size is a problem.  If you are using Windows for an operating system you must be using a CD having Windows XP with Service Pack 1 or Windows 2000 with Service Pack 3 or later in order to properly partition and format the drive.  Earlier versions do not have 48 bit LBA.

 

Thank you Sir. Detected and works great now.

Glad I could help.