How to Modify the Video Refresh Frequency in the Registry

ID: Q216166

The information in this article applies to:

Microsoft Windows NT Workstation versions 4.0, 4.0 SP1, 4.0 SP2, 4.0 SP3, 4.0 SP4
Microsoft Windows NT Server versions 4.0, 4.0 SP1, 4.0 SP2, 4.0 SP3, 4.0 SP4
Microsoft Windows NT Server, Enterprise Edition versions 4.0, 4.0 SP4

IMPORTANT: This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs. For information about how to do this, view the "Restoring the Registry" Help topic in Regedit.exe or the "Restoring a Registry Key" Help topic in Regedt32.exe.

SUMMARY

Some video drivers for Windows NT may not support the Refresh Frequency box feature on the Settings tab in the Display Properties dialog box. However, you can control this setting using a Windows NT registry value.

MORE INFORMATION

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys And Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it. If you are running Windows NT, you should also update your Emergency Repair Disk (ERD).

To change the monitor refresh rate using a registry value:

Click Start, click Run, type regedt32, and then click OK.

On the Windows menu, click HKEY_LOCAL_ MACHINE on Local Machine.

Double-click the
```
System\CurrentControlSet\HardwareProfiles\Current\System\CurrentControlSet\Services 
```
folder. Double-click the folder for your video driver (for example, if you have a video display adapter that is based on the S3 chip set, double-click the S3 folder), and then click the Device0 folder.

If there is no DefaultSettings.Vrefresh value, go to step 5. If there is an existing DefaultSettings.Vrefresh value, double-click the value and then type a numerical setting (from the table below) that is supported by your monitor in the Data box, and then click OK. Go to step 7.

If the value does not exist, click Add Value on the Edit menu, type DefaultSettings.Vrefresh, click REG_DWORD in the Data Type box, and then click OK.

Type 3c in the Data box, click Hex, and then click OK.

Quit Registry Editor, and then restart the computer.

NOTE: The refresh frequency must be specified in hexadecimal. Refer to the table below for common monitor refresh rates and their equivalent hexadecimal values.

Refresh Rate (in MHz)

Decimal	Hexadecimal
50	32
55	37
60	3c
65	41
70	46
75	4b
80	50
85	55

Additional query words:

Keywords : kbdisplay kbenv
Version : winnt:4.0,4.0 SP1,4.0 SP2,4.0 SP3,4.0 SP4
Platform : winnt
Issue type : kbhowto