AgpCPQ.sys is not only related to the AGP bus. This system file works between Windows and the ACPI (advanced computer power interface) tables in your motherboards NVRAM. It is loaded by Windows after MUP.sys in safe mode.
AgpCPQ.sys can cause Windows to malfunction, and fail to start which is why I am writing this wiki. There is more than one cause for this malfunction, and all causes will be discussed here. AgpCPQ.sys is also related to Agp440.sys.
Each of these has been known to cause errors on startup with AGPCPQ.sys and AGP440.sys
- Corrupt ACPI bios tables - Specifically on Phoenix Award BIOS's, when the ACPI tables become corrupted, Windows will not start or restart. While the ACPI tables are corrupted, the computer will not boot any operating system that uses any ACPI functions, including Live CD's, other hard drives, network boots, and USB boots. (this problem I was unable to fix at all)
- FAT32 file system corruption - Another cause of this problem occurs with the use of FAT32 drives that contain windows.
- Corrupt agp440.sys and agpcpq.sys - If the files are corrupt or damaged
Below are POSSIBLE solutions to the agpCPQ.sys error
- Corrupt ACPI bios tables AgpCPQ.sys fix (very hard to fix)
- Reset BIOS settings
- Try to flash (upgrade) the BIOS version
- New motherboard
- FAT32 corruption with AgpCPQ.sys freeze
- Convert to NTFS using a boot disk
- Reformat and reinstall Windows on NTFS
- Corrupt agp440.sys and agpcpq.sys files
- Windows Repair (reinstall those files) Microsoft Guide
- WORKAROUND FOR ALL AGPCPQ.SYS PROBLEMS
- go into BIOS setup, and disable everything in integrated peripherals, and disable ACPI if its an option, save and reboot.
If the computer will not boot normally with this error and safe mode stops at this point, sometimes it will continue to load in Safe Mode and Last Known Good Configuration after about 15 minutes.