That's right. Window's services can't interact with the desktop unless they are explicitly allowed to do so. Goto services from Control Panel. In the windows services UI right click > Properies on the service you want to change. Choose the Log On tab, choose local system account, and check the Allow service to interact with the desktop.
Thank you, Charlie.
We did as you suggested. But because JBoss service was running as "LOCAL SYSTEM" while Adobe Reader was running as me, even "Allow service to interact with the desktop" didn't get them interacting with each other.
Finally, we changed JBoss Windows service to run as me and it worked. (We opened the service's Properties and selected "Log On:This Account" and entered my system login.)
But, we are having a new yet bigger problem:
We tested 88 users before we made JBoss Windows service change and they all passed (without the need of Adobe Reader).
We tested 88 users last night (after JBoss Windows service change and without the need of Adobe Reader), we completely failed. At one point, the system CPU usage reached 100% and stayed 100% for a while. So all users were failed out.
My new question now is:
Is it possible that JBoss Windows service running as me instead of LOCAL SYSTEM causing CPU problem?
Thank you for any suggestions or advise.