Hitachi Deskstar 80g read 42g on Optiplex GX520

Certain Dell PCs use have a Media Direct button or Media Direct feature for loading the operating system (Windows Xp was native with these options) and drivers for the DVD player directly instead having to turn the computer "ON" and having it load everything.  The idea was if someone wanted just to play a CD or video, less would be required of the user..........

That being said, these particular PCs and possibly others without the Media Direct feature use "HPA" on the hard disk drive (HDD).  The HPA is the "host protected area", which these Dell PCs utilized for the Media Direct function and storage of the DSR (Dell System Restore) feature, which also came with the PCs.  This allowed the user to basically restore a corrupted or damaged OS or series of programs using a couple of keystrokes..........

The problem you have probably encountered is that in cloning or copying exactly, your HDD to the new 80 Gb or 250 Gb drives is that the MBR (master boot record) was also copied, telling the BIOS in your PC that the new drive is the same as the old drive, though it in reality, is not.  You need to recover the unallocated space taken up by the HPA.  This can be done a couple of ways.  I understand that the Optiplex series of PCs are desktops, is that right?  If so, hopefully you have room for a second HDD, so you don't have to swap out drives.  If you only have one drive bay, you'll have to swap out HDDs AFTER you create the utility CD.

Download the "CD IMAGE" utility from the HGST (Hitachi) web site under the "Feature Tools" set of programs.  This is a free HDD utility which is designed for checking and restoring certain Hitachi / HGST drives, but will work on many others.  Once you have downloaded this file, burn it to a CD, which will create a bootable version for use.  Install the HDD you wish to "repair" into your PC and then boot from the CD.  Follow the prompts and (if your HDD is detected and the options for checking the disk or repairing it appear, you're in luck) click on "Restore Capacity".  This should remove the HPA from the drive and make the unused portion available as unallocated space.  Once you have done this, exit from the program and TURN OFF your PC.  If you only have one drive bay, re-install the main HDD in your PC and boot normally.  Install your second, "repaired" HDD in an ATA external enclosure.  If you have two drive bays, just boot normally to the main drive.  Right Click on the "My Computer" or "Computer" desktop icon and then select "Manage" from the  pull down menu.  When the new window comes up, select "Disk Management" under the "Storage" heading.  A pictograph of your drives will show up.  Drive "0" or your "C:" drive will show on the top, your other "new" drive on the bottom.  The full size of the drive should show.  You'll have a partition of 42 Gb which is what that drive has utilized when you originally copied to it, and then you should see the remaining space as "Unallocated."  You may need to format this space.  Try to create a "Primary" partition by right clicking on the unallocated area and choosing the option(s) shown.  If this does not work, format that area.  Then create a new primary partition.  When this is done, if the drive does not have a drive letter (name) associated with it, assign one to it.  Depending on the number of drives and devices you have connected to your PC, this may show up as "New Drive E:" or "F:", etc.  Once you have created the new primary partition and assigned a drive letter name to your HDD, use a partition management tool to merge the partitions into one, primary, NTFS partition.  This should hopefully resolve your problem.

When you are done and wish to use the restored drive(s) as the destination, use a program like Norton Ghost (15.0 is the current version and is backwards compatible with Win Xp) to "Image" your drive; DO NOT CLONE IT, or you will again copy the MBR and HPA to the destination drive.  Good Luck - - let us know how you've made out.