SMS: Explanations of Remote Control Screen Acceleration

ID: Q200430

The information in this article applies to:

Microsoft Systems Management Server version 2.0

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

Before the current upgrades to Windows NT, capturing video for use in a Remote Control session was a simple matter of capturing video from the driver itself. Later versions of Windows NT have video hooks moved into the operating system kernel.

CAUTION: Loading new video driver names into the Windows NT Accelerated Drivers List may result in unexpected Blue Screen error messages. Test the compatibility of each new video driver name on a single client with a matching version of the video driver before adding a new name to the accelerated list. Be sure that testing has been performed on a smaller scale before implementing acceleration of a new driver across your enterprise.

MORE INFORMATION

Video Acceleration is determined by two items: 1) whether the video card is "resolved" to be similar enough to be accelerated by a driver in the "Video Accelerator" and 2) Video acceleration is turned ON. The list of video cards and drivers that can be accelerated is located on the Systems Management Server primary site under the following tree structure:

Start Systems Management Server Administrator Console.

In the Administrator UI, locate SITES, select your site site_code:site_name, click Site Settings, and then click Client Agents.

Right-click Remote Control Client Configuration in the Results pane.

Click Properties on the shortcut menu.

Click the Advanced tab and select Install accelerated transfer on Windows NT clients.

Click Apply and then click OK.

The Advanced tab also contains the list of video cards that can be accelerated. You can theoretically add to this list. Deleting items on this list removes them from video cards that will be accelerated -- even if acceleration is enabled globally.

Acceleration on computers running Windows NT is accomplished with either the Idisntkm.sys (for Windows NT 4.0) or Idisnt.sys (for Windows 3.51). The appropriate driver for the operating system is loaded into the appropriate Winroot\System32 directory (Winroot\System32\Drivers for Windows NT 4.0) and installed as a service to manage video acceleration during a Remote Control session. At no other time is the acceleration a factor in the Windows NT computer. Although the driver is loaded and running, it is not "used" except during an accelerated Remote Control session.

The actual "evaluation" process to determine whether a client's video card can be accelerated happens at the time Remote Control is installed to the client. To see if acceleration is enabled on a particular client, check the registry key below.

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).

Using either Regedt32.exe or Regedit.exe, locate the following key:
```
HKEY_LOCAL_MACHINE\Hardware\Devicemap\Video 
```

Check each of the "\Device\Video0" keys (note that there may be one or two of these) and take note of the Services\video driver\Device0 key on each.

Using the previous key(s) as pointers, now go to the following key:


HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\<key value from Step 2 above>\Device0

Make sure the InstalledDisplayDrivers key is set to either an entry by itself (as in "VGA") or multiple entries separated by a single space (as in "idisnt vga idisnt vga256").

Alternatively, if it is present and visible on the client's desktop, double-click the Remote Control indicator icon to get the status display window. If acceleration is loaded, the Remote Control status window will show that acceleration is loaded in the appropriate status line.

Additional query words: prodsms

Keywords : kbSMS200 smsremtshoot
Version : winnt:2.0
Platform : winnt
Issue type : kbinfo