Windows 7 - Cleaning up old drivers

I recently upgraded my motherboard and CPU and attached my existing hard drive. Windows 7 detected all of the new hardware and is running beautifully, but I just want to clean up remnants of old drivers for peace of mind. I already enabled Device Manager to show hidden devices and deleted the unused ones. The boot log, however, still shows a handful of unloaded drivers. I listed a few below. The NVIDIA GeForce GTX 275, for example, is no longer present. It doesn't appear in Device Manager, so where else might it be referenced?

Did not load driver @battery.inf,%*compbatt.devicedesc%;Microsoft Composite Battery
Did not load driver @battery.inf,%hid_device_battery.devicedesc%;HID UPS Battery
Did not load driver @cpu.inf,%intelppm.devicedesc%;Intel Processor
Did not load driver @hal.inf,%acpi_amd64.devicedesc%;ACPI x64-based PC
Did not load driver @oem1.inf,%xfi.devicedesc%;Creative X-Fi Audio Processor (WDM)
Did not load driver @oem46.inf,%nvidia_dev.05e6.01%;NVIDIA GeForce GTX 275

Personally, when I switch motherboards, I do a clean install.

No offense, but experience tells me otherwise. The only "clean" install I've done in the last 15 years was XP -> 7 and only because an in-place upgrade wasn't supported. I've swapped the core hardware four times in Windows 95, 98 SE, XP, and 7 without a major hitch, and everything still runs great. Windows is designed to handle hardware changes like this. That's why it boots right up (okay, sometimes requires switching disk controller to standard drivers first), detects the new hardware, deactivates the old drivers, and continues on its way. I keep things pretty clean (e.g. remove unnecessary startup items) anyway.

I was mistaken anyway. I was looking at old entries in the boot log. Actually these are the only drivers not loaded:

Did not load driver \SystemRoot\SysWow64\drivers\dsload.sys
Did not load driver \SystemRoot\System32\DRIVERS\srv.sys
Did not load driver \SystemRoot\System32\Drivers\NDProxy.SYS
Did not load driver \SystemRoot\System32\drivers\vga.sys
Did not load driver \SystemRoot\system32\DRIVERS\serial.sys

If there is no reason to worry about doing a clean install on hardware swaps, then why be concerned with cleaning up old drivers?

You can not be sure that you got every bit of old drivers entries removed completely as to not be of concern at some point.

Space is not really that big an issue any longer.

It is always advised, that in the long run, it is better to clean install when swapping Motherboard and CPU due to different chipsets etc.

If/when in the future one does have an issue, no one, I do not care who they are or where they come from or what their background is, can guarantee that driver conflicts would absolutely not be the cause.

The only things not of real concern ,swaps of the following , RAM, HDD, Optical Drives, Sound Cards (usually, but not always) and Video Cards (usually, but not always), other misc devices.

Why be concerned with cleaning up old drivers? I don't know, OCD? Perfectionism? I'm no more worried about it than about getting a haircut.

Advised by whom? I've heard from computer "experts" who said they do complete reformats and reinstalls every 2 or 3 months for no good reason. There are hundreds of web pages documenting the in-place upgrade process without installing from scratch.

The chipset has little to do with anything. Windows detects the new chipset and stops using the old drivers just like other hardware. Even if old driver files are lying around, there's no conflict or other harm if they're disabled.

Four times I've successfully changed core hardware without wasting time reinstalling operating systems and software. How many times have you tried it?

Finally, back to the boot log, it turned out that there were only a few "did not load" entries, and they were all present before the upgrade. Everything is clean.

Right,, but because it has worked for you without issue, it will always do so. Sorry to burst your bubble.
But, ....... It is not always that smooth.

I stand by my posts. It is recommended to do a full reinstall when,....,,....,,...