Install a larger hard drive on a Dell su9300. That stock drive is only 128gb and I need more.

Go to your Admin Tools, computer management, disk management and if it shows up there but with a black line across the mini window it showing in, it will need to be enabled for windows to see it. if nothing like that is working, it may just be a bad drive. kingston 128Gb flash drives may not be formatted correctly for windows to see that its plugged in

Hard Disk Upgrade Can I upgrade or install a larger hard disk drive in my Viewer?

The P-5000 includes an internal 80GB hard drive which is specifically designed to work with this product. There are no hard drive upgrades available for this product. If you try to install another hard drive, it may damage or adversely affect the operation of the product. This type of damage or operational failure is not covered by the product's warranty.

make use of the warranty by taking it back to the supplier.

When you install a new hard drive you need to install also a software to make your drive working. The new install hard drive does now contain a copy of windows software.

A better recommendation is to use a program like Acronis, to copy your current OS image from the existing drive to a New larger drive, and install the larger cloned drive as the C: and format the old drive as D: for extra storage. If you don't feel comfortable doing it, that is a project that Geek Squad should be able to do for you.

this time external hard disk drive to you Dell... this Dell optimized for only that 10GB drive..

Hi there,
as long as you have the windows COA code on the back of the computer (certificate of Authenticity) you can just find a good copy of XP Pro, and install it on your machine. When done, you can run the resorce CD and install the drivers.

If you do not have the Operating System disk, you have to find another disk, or contact Dell to get a new one sent to you.

The key is that you have the code on the back of the computer (or top, or side, or wherever.)

Good luck!

The BIOS can sometimes be a limiting factor when upgrading to a larger drive so I would check if you have a flash BIOS that can be upgraded to accommodate more memory or larger drives. The utility used for upgrading would have to come from Dell's website. 
To characterize your system in detail, I recommend using Belarc Advisor:
Belarc site 

The ATA-5 Specification barrier According to the ATA specification, any drive over 7.88GB (8.46 billion Bytes) is supposed to report its "geometry" as 16383/16/63 (C/H/S). Which enables old software to access the first 7.84 to 7.88GB of such a drive, using CHS addressing and the BIOS Int 13h system call. And while a P-CHS over 16383/16/63 can be used to access all the drive capacity-- up to the ATA-5 128GB limit-- that is not the recommended way to do so. Rather, LBA addressing should be used to access those larger capacity drives. (Or at least any partition that goes over the 7.88GB BIOS Int 13h CHS barrier.)
So, LBA uses a 28 bit binary number to specify the sector number on a drive. Thus:

228 = 268435455 Sectors

268435455 Sectors x 512 Bytes/Sector = 137438952960 Bytes

Resulting in the 128GB (137.4 billion Bytes) ATA-5 size limit.

You would have to contact dell for the OS disk.

I dont think you can install the hard disk in place of floppy drive. An external Hard disk would be a better option.