Just installed a 2nd hard drive in a Compaq Presario running Windows XP Home Multi Media. It's an 80GB but now formatted it shows only 31.4 GB with no more space available. Any ideas on how to get the full capacity back?

XP Home multi media?

You mean XP Media Centre Edition?

Right click on the " my computer" icon and choose manage. One of the tabs on the left should be labelled something like "Local volume / Disk management". Post a screenshot of that page here.

I think you have reached the maximum capacity, which your IDE controllers recognize. I'm not sure what could the other reasons be but any Harddisks won't show size errors this way until and unless u reach the maximum capacity which in many cases is 120GB or you have formatted only that much section incorrectly using any other partioning manager as fdisk in linux.

Go to My Computer Icon and right click. select manage. Select Disk Management. In that checkout how much is shown for your disk drive.

If your pc is old (circa 2000) then its bios probably has a cap of 32gb.

Try updating your BIOS maybe if this is the case?

Modern machines have a cap of 320 i think

Capacity of your first hard drive, please?

Desktop or Laptop?

Yes it's Media Center.
Attachment shows screenshot of configuration.

No barrier limits on your system. Wrong configuration on your hard disk. You have just jumpered the second hard disk incorrectly.

The second disk has to be set to slave and the first hard disk (one windows is on) has to be set to master. Use tweezers or long nose pliers to move the plastic tab on the back of the drive so that it connects a different set of pins. The drive casing istelf should have a chart depicting master/slave jumper arrangements

Thanks. We'll try other jumper pin locations for the tab. Don't think there was a chart on the disk casing but we'll check, otherwise trial and error.

Where did you put your second hard drive? Is it in the middle connector of the ide ribbon of the primary ide controller?