Apparently Windows XP's Remote Desktop service does not support running the RDP service in 32-bit mode. I learned this today after a long struggle trying to get it to work, and the best I ended up with was 24-bit mode after some Group Policy edits.
How did this come about?
Today, given Second Life's failure to support Microsoft Vista Ultimate or any version of Vista, I wanted to install it on a Windows XP system. Since my other computer runs Windows XP and I Remote Desktop (RDP) into it for control, it made perfect sense to use it for Second Life. However, when trying to run Second Life, it returned an error message:
Second Life requires True Color (32-bit) to run in a window. Please go to Control Panels -> Display -> Settings and set the screen to 32-bit color. Alternately, if you choose to run fullscreen, Second Life will automatically adjust the screen each time it runs.Odd, in my opinion since I knew the video card supported high resolutions including a 32-bit display.
The issue immediately pointed to the use of Remote Desktop (RDP), since when I was in the Remote Desktop session I noticed that the color mode was only 16-bit. I double checked my Remote Desktop settings on the display tab and they were set to 1280x1024 display and Highest Quality (32-bit).
What was the summary?
The bottom line was the best I could acheive in Windows XP through Remote Desktop (RDP) was a 24-bit display. Apparently you need to connect to Windows Vista or Windows 2003 server to acheive the 32-bit display through a Remote Desktop Conncetion (RDC). This means that I cannot run Second Life through Remote Desktop. If your programs require 24-bit mode, it can be accomplished.
Here are the details of items you can verify and modify to get the most out of the display through Remote Desktop and Windows XP.
First, you can verify your Remote Desktop Client software supports 32-bit mode. KB925876 at Microsoft (http://support.microsoft.com/kb/925876) clearly states that the Remote Desktop Client 6.0, supports 32-bit video.
Visual improvementsSo, if you do not have 6.0 of the client, visit the Microsoft site and download it.
Remote Desktop Connection now supports 32-bit color and font smoothing.
To enable 32-bit color, follow these steps:1. Click Start, click All Programs, click Accessories, click Communication, and then click Remote Desktop Connection.
2. Click Options, click the Display tab, and then click Highest Quality (32 bit) in the Colors list.
To enable font smoothing, follow these steps:1. Click Start, click All Programs, click Accessories, click Communication, and then click Remote Desktop Connection.
2. Click Options, click the Experience tab, and then click to select the Font smoothing check box.
Secondly, and most importantly -- Remote Desktop server on Windows XP only support up to 24-bit video through a RDP session. However, by default it only runs in 16-bit! It is, however possible to change it by tweaking a group policy setting in Windows XP. To do this:
1. Open up the Group Policy editor, by going Start --> Run and type in MMC.
2. Add the Group Policy snap-in by going File --> Add/Remove Snap-in --> Add --> Group Policy Object Editor --> Add --> Finish (Local Machine) --> Close --> Ok.
3. Now navigate in the Group Policy Object Editor from Local Computer Policy --> Computer Configuration --> Administrative Templates --> Widnows Components --> Terminal Services and double-click on the 'Limit maximum Color Depth' object.
4. By default the policy is disabled and sets you to 16-bit color. Click on 'Enable' and choose either 'Client Compatible' or 24-bit to enable the highest resolution of 24-bit (True Color) to display via Remote Desktop. Options include 8-bit, 15-bit, 16-bit, and 24-bit.
Now you should be able to run in up to 24-bit on Windows XP via your Remote Desktop connection!