This is a perpetual problem. When I "exit" the Zimbra Desktop app, both zdesktop.exe and zdclient.exe remain running as seen from the task manager and prevent XP Pro from gracefully shutting down. I get the really annoying "Dunh!" sound even though I have system sounds shut off and then I have to be on hand to click the "OK" button instead of just walking away while it takes a minute to shut down. Really annoying!
I found the following workaround:
1. Create a batch file with a text editor. Call it what you want, say, killzimbra.bat. Add the following lines:
taskkill /f /t /im zdesktop.exe
taskkill /f /t /im zdclient.exe
and save the batch file. Be sure the extension is .bat .
2. Click Start->Run. Type in gpedit.msc . Go to Local Computer Policy->Computer Configuration->Windows Settings->Scripts(Startup/Shutdown). Double click Shutdown. Click Add. In Script Name: box enter path to killzimbra.bat or Browse to it. Click OK. Click OK again then close Group Policy editor. You will have to reboot for this to take effect. Now when you shut down, these two files will be terminated so you can just walk away as usual. Not a solution but hey, it works.