crazijoe

So you can only get you computer to show 137GB on that 500GB drive. This can be a limitation of either the system motherboard BIOS or the OS itself. This all has to do with LBA or Logical Block Addressing. I don’t want to go too deep into the technology aspects of this so I will just briefly cover it.

28 bit LBA will only support drives up to 128GB.
48 bit LBA will support drives up to 128PB or 128,000,000GB

Native WinXP and Win2K (no service packs) will only support up to 137GB. This is because they only support 28 bit LBA. This was addressed with service pack 1 for WinXP and service pack 3 for Win2K.

http://support.microsoft.com/kb/305098
http://support.microsoft.com/kb/303013

If you have a Windows OS install disk without a service pack, you can slipstream the service pack into the install CD.

http://www.techsupportforum.com/showthread.php?t=120956

This will enable you to format the entire drive during the initial install of the OS.

Most motherboards, manufactured after 2004, will support 48 bit LBA. If it does not, you may need to check with the manufacturer for a BIOS upgrade. If the motherboard is to old, you have several options. The most preferred is to get an optional PCI IDE controller card. This will remedy the problem since the controller card will have 48 bit LBA support and does not rely on the motherboard BIOS. The other option, and the one that is not recommended, is to install DDO.


DDO or Dynamic Disk Overlay is merely a Band-Aid and I would not trust it for what its worth. It actually does not fix the problem at hand.

DDO is a software translation driver to allow access to the full capacity of the hard drive. It also goes by names like Big Drive Enabler, Disk Manager, EZ-Drive, etc.. The idea behind one of these programs is pretty simple: they override, in software, some of the BIOS code in your motherboard or hard drive controller, allowing access to the full size of a new hard drive on an older system. In otherwords it "fakes" the system so it can see the size of the drive.

The software must be loaded immediately when the machine is booted, to ensure that the driver is in place before any other piece of software tries to access the drive. Otherwise, the drive will not work properly. To ensure that they are always loaded immediately at boot time, the installer, for this sort of program, modifies the boot drive's master boot record and installs the driver at the beginning of the disk.

Word of caution. Do not believe that using these type software drivers (DDO) is as good as proper BIOS support. It isn't. There are numerous problems associated with using these drivers for large disk support, which is why I do not recommend their use. Here are just a few:

Compatibility Problems: When you use one of these drivers they essentially set up their own logical disk volumes using a non-standard format. This means you are not using your disks the standard way. This isn't usually a problem in and of itself, since most operating systems know about these drivers, but the potential for incompatibility exists.
Reduced Drive Interoperability: The drivers that come with the various manufacturers' drives are normally customized for that manufacturer's equipment only. This means that if you put a Maxtor drive in your PC and later want to add a Seagate, for example, you may have a bit of a problem. You will have to at this point probably purchase the full version of something like Disk Manager, and for the extra cost you will be better off buying an add-in hard drive controller.
Problems Removing the Driver: Some of these overlays can be very difficult to remove from the disk, and require you to use uninstall facilities that come with the driver, if you want to get rid of them. When you do remove the driver, say because you have upgraded to a PC that supports large drives, you may have to zero fill and reformat the drive (though this may not be required).
Floppy Disk Booting Complications: Because the driver is located on the hard drive, you must boot from the hard drive to load it. If you boot from a floppy, your hard drive may seem to "disappear" because the overlay wasn't loaded. The driver will allow you to boot from a floppy, but you must do it by booting the hard drive, waiting for the overlay to load and a message to be displayed that says "To boot from a floppy disk, press the space bar", and then put the floppy into the drive and press the space bar.
Operating System Installation Issues: The drive overlay located on the hard drive can cause problems when using alternative operating systems, attempting to set up a multiple-OS system, and so on. You must verify that every operating system that you install is capable of handling the driver you are using.
I have also found that doing data retrieval on a drive with DDO, that the data is unrecoverable.
Most of the time these drivers will work OK. Especially if you are not doing anything too unusual with your PC. It is not the best way to deal with BIOS translation, given that much more reliable, and relatively inexpensive, hardware solutions exist, such as an add in PCI controller.