citrix how to change session timeout

The easiest way to accomplish this is by configuring the ICA properties on the presentation servers themselves via All Programs -->Administrative Tools --> Terminal Services Configuration.  Although it needs to be done one each Presentation Server separately, it is better than trying to use the TS components on a GPO setting, because the standard GPO setting affect both RDP and ICA and may have some unintended effects on Citrix (here is a good article onthat topic): http://www.msterminalservices.org/articles/RDP-GPO-Settings-Citrix-Servers.html)http://www.msterminalservices.org/articles/RDP-GPO-Settings-Citrix-Servers.html
The article also mentions creating a custom ADM if you want to use Group Policy, but it is easy to set this manually on each server if you dont have too many.

Thank you very much for your answer. How would I know if the previous administrator was using group policy to administer timouts in citrix? I checked the settings you said and they were not configured at all