When Windows XP's driver rollback fails with "previous driver not saved" errors, developers need surgical removal techniques. The OS's stubborn driver preference system often blocks manual downgrades, especially with audio drivers causing phantom devices and input failures.

Windows XP stores driver components in multiple locations:

%SystemRoot%\System32\drivers        # .sys files
%SystemRoot%\inf                     # .inf installation files
%SystemRoot%\system32\DriverStore    # Driver cache (Vista+) 
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services # Registry entries

For our audio driver scenario, follow this removal sequence:

:: Command Prompt (Admin)
devmgmt.msc
set devmgr_show_nonpresent_devices=1
devmgmt.msc

# Now in Device Manager:
1. View → Show hidden devices
2. Right-click problematic audio device
3. Uninstall → Delete driver software
4. Repeat for all related devices

Create a .reg file to remove remnants (backup first!):

Windows Registry Editor Version 5.00

[-HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\PCI\VEN_8086&DEV_2668]
[-HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E96C-E325-11CE-BFC1-08002BE10318}]

# Use PCI\VEN IDs from your hardware

For stubborn driver packages, use this PowerShell-inspired approach (adapted for XP):

pnputil -f -d oem*.inf
del %systemroot%\inf\*.pnf
del %systemroot%\inf\infcache.1

# Forces re-cache of driver information
rundll32.exe setupapi,InstallHinfSection DefaultInstall 132 %windir%\inf\machine.inf

When standard methods fail, boot to Safe Mode with Command Prompt:

cd %windir%\system32
ren drvindex.dat drvindex.old
ren drvstore.dat drvstore.old

After cleanup, verify with:

driverquery /v | findstr /i "audio"
sigverif.exe  # Check unsigned drivers

Then install your legacy driver package using:

rundll32.exe advpack.dll,LaunchINFSection yourdriver.inf,DefaultInstall

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When newer audio drivers cause more problems than they solve on Windows XP SP3 systems, the built-in rollback feature often fails with cryptic messages about "driver backups not existing." The OS stubbornly clings to its belief that newer drivers are superior, making manual driver selection attempts futile.

For complete removal, we need to attack the driver at its source. Open Device Manager (devmgmt.msc) and:

1. Right-click the problematic audio device
2. Select "Uninstall" and check "Delete the driver software for this device"
3. Reboot into Safe Mode (F8 during boot)

Sometimes driver remnants persist in the INF cache. Navigate to:

%windir%\inf
%windir%\system32\drivers

Search for files matching these patterns:

oem*.inf       (for manufacturer-provided drivers)
wdmaud*.inf    (for Windows audio drivers)

Before registry edits, back up with:

reg export HKLM\SYSTEM\CurrentControlSet\Enum\USB vid_xxxx_pid_yyyy backup.reg

Then remove these keys (adjust for your hardware ID):

HKLM\SYSTEM\CurrentControlSet\Control\Class\{4d36e96c-e325-11ce-bfc1-08002be10318}
HKLM\SYSTEM\CurrentControlSet\Enum\PCI\VEN_XXXX&DEV_YYYY

When installing the old driver, use this command to override version checks:

rundll32.exe setupapi,InstallHinfSection DefaultInstall 128 path\to\driver.inf

Or create a custom INF with these directives:

[Manufacturer]
%ManufacturerName% = MyOldDriver

[MyOldDriver]
"Old Audio Chip" = OldDriver_Install,PCI\VEN_XXXX&DEV_YYYY

[OldDriver_Install]
CopyFiles = DriverCopy
AddReg = DriverReg

Microsoft's devcon utility (from Driver Kit) can force removal:

devcon remove "PCI\VEN_XXXX&DEV_YYYY"
devcon dp_delete "Old Audio Driver Package"

For batch processing:

@echo off
set HWID=PCI\VEN_XXXX&DEV_YYYY
devcon remove %HWID%
devcon rescan
devcon install olddriver.inf %HWID%