When I tried to use the Citrix management console to remove an old server from my Presentation Server 4.0 farm, I got an error that said: "The Presentation Server Console failed to remove the server. Error Code:80000007"
Since using the console didn't work, I had to use the dscheck utility provided by Citrix to manually remove the server from the datastore. Here is the command to use, where servername should be replaced with the name of the server you want to remove from the farm (CAUTION: If you don't specify a server name, ALL servers in the farm will be deleted!):
dscheck /full servers /deleteall servername
