(Note: Booting the Dell Utility partition requires a recent Dell bios that includes a bios boot menu with that capability. If your bios does not have that capability, stop here, since there is little point in creating a Dell Utility partition on your computer. You can, of course, create a multiboot system with your own custom utility partition, but that's a different matter that doesn't use Dell's bios boot menu.)

You may wish to recreate the DE partition if the hard disk is upgraded or replaced. For the record, installing delldiag on the hard disk is optional. It's the same program you can run from the Dell Resource CD (if one came with your computer, and if you can still find it). Many people are satisfied to just run the diagnostic utility from CD when necessary, but the following steps explain how to recreate the DE partition on the hard disk if you choose to do so.

Unfortunately, Dell provides no easy way to restore or recreate the Utility partition. A good commercial partition imaging program (DriveImage, Ghost, BootIt-NG, TrueImage, et al) should have no trouble duplicating the DE partition from the old disk onto the new disk, so should be considered as a first resort. However, you may need to recreate the partition from scratch if the old DE partition was erased, the old disk is not readable or not available, or if you wish to upgrade to a newer version of delldiag, the Dell diagnostic program.

Here's how to recreate the unsealed version of the DE partition from scratch.

(Note to reader: a certain familiarity with DOS is expected here. Please don't ask me for help about basic DOS matters. The following is one way of doing things, but feel free to use your own methods to do the same things below.)

1. Make sure you have unallocated disk space in which to create the partition. This is not a problem on a new disk, but if the disk has existing partitions, you may need use something like PartitionMagic or Ranish Partition Manager to free up some disk space. A typical utility partition is about 30-60 MB.
   (Note to reader: although it doesn't appear to be strictly necessary, for compatibility I recommend locating the utility partition at the front of the disk.)

2. Make a Primary FAT16 partition. PartitionMagic (retail) and Ranish Partition Manager (freeware) are popular tools for this, or boot to a DOS floppy and use fdisk.

   If you are using fdisk, the choice is called a "Primary DOS" partition, and you will also need to perform a second step to separately format the partition. Reboot again and use the "format c:" command, which should default to FAT16 on a 30-60 MB partition.

   If you are using PartitionMagic, the FAT16 choice is simply called "FAT", and the utility formats the partition at the same time it is created.

3. Make the partition 'active' so it will show up as "drive C:" in the following steps.

4. Reboot so the changes are recognized.

5. Make the partition bootable. Boot from a DOS floppy, then "sys c:" to transfer the system files.

6. Copy the Dell Diagnostic program. The program (delldiag.exe) and its support files will be together in the same directory. Find these on the Resource CD or Utility CD and copy everything in that directory to C:.

   Or, download the delldiag program for your model from the Dell website, extract all files, and put them all in C:. If you have a choice, download the CDD*.EXE or CZ*.EXE version because it's easier to extract the files from those packages than from the CD*.EXE version. If you download an 'update' version of delldiag, you'll need to open the .EXE file with a zip program (such as PKZip or WinZip) and manually extract the files from the package.

   Note: the diagnostic program doesn't include config.sys, autoexec.bat, or dellboot.exe, so...

7. Add a reboot program. Dell uses one called dellboot.exe, but any old reboot program will do. There are plenty on the web, such as reboot.com, reset.com, warmboot.com, et al--grab one and put it in C:.

8. Create config.sys and autoexec.bat files. These are ordinary text files that run when the partition is booted, so use them to automatically launch delldiag.exe and then reboot at the end. Hopefully you know enough DOS to know how to do this. Here are the contents of the config.sys and autoexec.bat files Dell uses.

9. Change the partition-type byte to DEh. Boot to DOS, load a mouse driver, and run ptedit (which you can get here). From Step 3, the partition type should be '06'. Change it to 'DE'.

   (Note to reader: ptedit is tough to use without a mouse, so make sure you load a DOS mouse driver before launching ptedit.)

10. Make Windows the active partition. The active partition is the one marked 80h in the boot column of the partition table. If Windows isn't installed yet, install it now. (It will probably make itself the active partition in the process.) If Windows is already installed, use ptedit to change the Windows partition from Boot-type '00' to '80'. Remember that only one partition should be marked '80'.

This recreates the unsealed version of the DE partition, not the sealed version. (But why would anyone have a need to recreate the sealed version?)

Warning: If your computer is equipped with a Dell PC-Restore partition, that function expects to find the config.bts file in the DE partition so that it can return the computer to a sealed state following a restore of the operating system. You will either need to recreate that file, or edit the PC-Restore partition's autoexec.bat file so it skips returning the system to the sealed state.