Finally! Font Smoothing Over RDP/ICA on Server 2003

It took five years and probably lots of customer complaints, but finally one of the most important technologies introduced with XP/Server 2003 is available over the remoting protocols RDP and ICA: font smoothing aka ClearType.

If you have read other articles on this blog you know that I deem font smoothing indispensable on today’s LCD monitors. For some reason Microsoft included the technology in Server 2003, but decided not to make it available over RDP. This put Citrix in a difficult position – they could not enable font smoothing over ICA either because some key system component was missing. They had to wait for Microsoft to make the first move.

What You Need – KB946633…

Now, finally, this has happened. Microsoft released a hotfix that enables font smoothing over RDP by default. If you want to restrict your users to not being able to use font smoothing (maybe because of bandwidth considerations) you can set the following registry value:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows\TSEnableFontSmoothing=0

At least service pack 1 is needed in order to install hotfix KB946633 on Windows Server 2003. On the client side you need at least RDC 6.0.

In order for ClearType font smoothing to work it must not only be enabled per computer (see above, TSEnableFontSmoothing), but also in the remote desktop client and the user profile on the terminal server.

…Which You Can Even Get Online…

A while back Microsoft changed its policy with regards to “semi-private” hotfixes. In the past one had to call MS support, talk to them for a few minutes and would then get an e-mail with URLs to password-encrypted hotfix files which had then to be downloaded and unpacked with the current password contained in the e-mail. Sounds tedious? It was! Luckily this changed – a bit. “Semi-private” hotfixes like KB946633 can now be requested online without having to call MS support. Be sure to look out for the text “Hotfix Download Available” near the top of the KB article. But you still get an e-mail with the URL to the password-encrypted hotfix…

…and PSE450R02W2K3037

Just yesterday Citrix released its own hotfix for Presentation Server 4.5 on Windows Server 2003 that enables font smoothing. It needs to be installed on top of MS KB946633. Apart from making font smoothing available it fixes various issues in Presentation Server 4.5 R02 (rollup pack 2).

, , ,

6 Responses to Finally! Font Smoothing Over RDP/ICA on Server 2003

  1. Spoonman July 14, 2008 at 14:22 #

    Well, I wouldn’t say it was one of the MOST important features. In 8 years of being a Citrix administrator, I’ve only recently just received my request to enable it ever (ironically, the day before the patch was released, so I almost lied when I told them it wasn’t possible). We have over 14,000 users on our farm, and at my previous employer we had over 9,000. I’m sure if it was a real issue, someone would’ve noticed it before now. The only reason it’s become an issue for us now is we’re releasing a new version of our in-house written application that we are now providing to our customers via Citrix and so Sales is involved. :)

    I would think the main reason they disabled it was because not everyone’s using flat panels yet. IMO, anti-aliased fonts look worse on CRTs, so by enabling it for your Citrix-hosted apps, you’d be doing your users a disservice. And, as you pointed out in another article, there is a slight performance hit on bandwidth. I wonder how much of a difference it makes processor-wise, too? I guess we’ll find out once we enable it on our 150 user machines. :)

    Thanks for the info!

  2. Helge July 14, 2008 at 14:46 #


    I agree: the main reason ClearType font smoothing was disabled was probably that MS thought that LCD screens were not widely used yet. At least I cannot think of any other reason. However, around 2005 I worked in a relatively large (though not as large as yours) project upgrading existing farms to PS 4 and at the same time replacing fat clients + CRTs with thin clients + LCDs. I must say the customer was quite disappointed when I told him that ClearType just does not work.

  3. Dan Dar3 February 8, 2010 at 00:56 #

    I\’d say the main reason is that most users don\’t know about the feature although it might be enabled by default on their desktops (i\’m talking about standard Font Smoothing not necessarily ClearType) and second is it\’s because most TS / Citrix admins consider it unecessary / adverse effects on network bandwidth (this is what I got from my IT team) and they want to avoid potential problems. I\’d say this should always be there and somehow disable it in the RDP/Citrix client if the network latency is too high, rather than just have it disabled for all, but maybe that\’s just me, being a user and developer…

Leave a Reply