What you recommended may be a solution, but let me quote the "Perform a Custom Installation of Windows 7" paragraph from the "Upgrading From Windows XP to Windows 7", page 7: This is the procedure I followed closely:
"1. With your PC on and Windows XP running, do one of the following:
* If you have a Windows 7 installation disc, insert the disc into your computer. Setup should start automaticallyi. If it doesn't, click Start, click My Computer, open the Windows 7 installation disc on your DVD drive, and then double-click setup.exe.
2. On the install Windows page, click Install now.
3. On the Get important kupdates for installation page, we recommend getting the latest updates to help ensure a successful installation, and to help protect your computer against security threats. Your computer will need to be connected to the internet during Windows 7 installaltion to get these updates.
4. On the Please read the license terms page, if you accept the license terms, click I accept the license terms, and then click Next.
5. On the Which type of installation do you want? page, click Custom.
6. Choose the partition containing Windows XP (this is often the computer's C: drive), and then click Next. (Do not select your external USB hard drive) [WHICH PROBABLY EXPLAINS WHY IT NO LONGER SHOWS UP THERE AS A CHOICE.]
7. In the Windows.Old dialog box, clkck OK
[I NEVER GOT THIS FAR BECAUSE OF THE FLAG ON LOADING THE PRIMARY IDE CHANNEL DRIVER. HOWEVER... YOUR ADVICE FORCED ME TO FINALLY REALLY READ THE FINE PRINT OF THIS TUTORIAL ON UPGRADING XP TO WINDOWS7. A KEY PARAGRAPH BEGINS WITH "TROUBLESHOOTING INSTALLATION PROBLEMS." IT READS:]
TROUBLESHOOTING INSTALLATION PROBLEMS:
"If an eror message states that Windows can't be installed to the partion you chose, and Show Details reveals a dialog box that says, "Windows must be installed to a partition formatted as NTFS," then your computer's hard disk is likely formatted using the older FAT32 file system.
[NOTE: THIS IS NOT THE ERROR MESSAGE I GET, IN FACT, I AM PRETTY SURE THAT I CONVERTED TO THE LATER FILE SYSTEM SOME TIME AGO. WOULD IT BE WORTH TRYING THIS BEFORE I DO SOMETHING AS DRASTIC AS CLEANING OFF MY C: DRIVE?]
I've read the Microsoft custom installation guide for upgrading from XP to Windows 7 as well as custom installation guides on a number of independent web sites. If your 8100 shipped with Windows ME originally installed on the hard drive and you later upgraded to XP Pro then it's quite possible that drive C: is still formatted FAT32. You can easily check by having a look at the drive properties in My Computer. If it is FAT32 I'd definitely try converting the file system to NTFS then attempt to custom install Win 7 again to see if it works (despite the fact that the message you get isn't the same as the one in the troubleshooting section of the guide). If it doesn't then you're back to the formatting drive C: option.
Took a few days breather. Can only stand computer problems for so long and had numerous computer jobs to crank out.
I finally found an indication of file type using third-party software (ATI Catylyst Control Center)... I never did find it through "My Computer". It indicates that all hard drives ARE NTFS. Before I take the (sounds like) drastic step of reformating my C: drive, did any other solutions pop up since our last exchange? Does Dell or Microsoft have any solutions? (This problem must have surfaced hundreds of times by now.) What, for example, will the W7 UPGRADE software do with a clean drive when it is expecting Vista or XP? Will the computer even boot up with just the Windows7 upgrade disk?
I understand the need to take a break from this stuff occasionally. I'm getting ready to start a new IT job at a medical school here on Monday so I'll be hip deep in computer issues for a good while.
Since you've determined drive C: is NTFS I think we can move away from the file system being the reason you're being prompted for a Primary IDE channel driver. Given that the Windows 7 upgrade media gives the option of doing a custom install by formatting the hard disk I should think it would be able to complete the installation since the setup program would have already confirmed you had Windows XP due to the fact that the upgrade was started by running the Win 7 disc from within Windows XP.
One last thing I tried was to update the BIOS from B02 to B09. Again tried the W7 upgrade with the same results... it is still looking for the Primary IDE Channel rider. Then I finally made the decision to go ahead, cut the limb off behind me and format the C: drive in readiness for a normal upgrade to a clean drive. I clicked the "run" command, told it to "format C: drive" and it first told me that I needed to dismount the drive. When I answered "Y" to that, it tried to dismount it, told me it was busy and could not dismount it. If you think I should still aim toward reformatting the C: drive, how do I get it to unmount?
If we get it formatted and then the W7 disk will not boot, I've got an older XP disk (don't know where the most up to date one went) so hopefully I can recover if needed.
The dismount message appeared because you attempted to format drive C: from within Windows, so you are using the drive you're attempting to format. This is what caused Windows to display the message that the drive is busy. A mounted drive in Windows is any active hard drive and the error occurs if you try to format the drive Windows is installed on while in Windows. You'll need to boot to the Win 7 disc and run setup from there to successfully format the C: drive.