You receive a "Cannot install this hardware" or "An error occurred during the installation" error message when you try to install a PCI device

When you try to install a new Peripheral Component Interconnect (PCI) device or a PCI device driver, you may receive one of the following error messages: For example, you may receive one of these error messages if you try to install a PCI modem or a PCI modem driver.

This issue may occur when one of the following conditions is true:

• A registry subkey does not have the default permissions set correctly. The default permissions may have been changed.
• The installer for your device requires additional permissions that are more lenient than the default permissions.

Note The following list contains the relevant default permissions for subkeys in the registry:

• Everyone: Read
• System: Full Control

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:

Method 1: Restore the default settings to the registry subkey for your device

If you can determine which subkey is related to this issue, edit the registry to configure the correct settings on that subkey. For information about how to troubleshoot this issue and determine which subkey is affected by this issue, see the "More Information" section. To configure the correct settings on a specific subkey:

1. Log on to the computer by using an account that has administrative credentials.
2. Click Start, click Run, type regedit in the Open box, and then click OK.
3. Locate the following registry key:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\ENUM\PCI
4. Right-click the subkey that is related to the device that is experiencing the symptom, and then click Permissions.
5. Click Advanced, and then click the Permissions tab.
6. Make sure that the following default permissions are configured:
   • Everyone: Read
   • System: Full Control
7. Click to select the Replace permission entries on all child objects with entries shown here that apply to child objects check box, and then click Apply.
8. Click Yes, and then click OK two times.
9. Quit Registry Editor.
10. If the issue is not resolved, repeat this procedure, and grant full control permissions to the Everyone group on this subkey.

Method 2: Restore the default permissions for the PCI key and for its subkeys

1. Log on to the computer by using an account that has administrative credentials.
2. Click Start, click Run, type regedit in the Open box, and then click OK.
3. Locate the following registry key:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\ENUM\
4. Right-click PCI, and then click Permissions.
5. Make sure that the following default permissions are configured:
   • Everyone: Read
   • System: Full Control
6. Click Advanced, click to select the Replace permission entries on all child objects with entries shown here that apply to child objects check box, and then click Apply.
7. Click Yes, and then click OK two times.
8. Quit Registry Editor.

For advanced troubleshooting, configure the Setupapi.log file to use verbose logging, and then try to install the device driver.

Note Verbose logging increases the size of the Setupapi.log file. We recommend that you only use verbose logging while you troubleshoot problems. When you have finished, delete the LogLevel value to turn off verbose logging.

The log may record exactly which registry subkey is related to the symptom that this article describes. To configure verbose logging:

1. Log on to the computer by using an account that has administrative credentials.
2. Click Start, click Run, type regedit in the Open box, and then click OK.
3. Locate the following registry key:
   HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Setup
4. Right-click Setup, point to New, and then click DWORD value.
5. Type LogLevel to name the new value, and then press ENTER.
6. Right-click the LogLevel value that you just created, click Modify, type 0xFFFF in the Value data box, and then click OK.
7. Rename the existing Setupapi.log file to Setupapi.old.