I checked the Eventlog on the Exchange Server and on two of the client computer that experience the problem, but I did not find any entries that seemed related to it. Well, one user is located at a branch office, but he is the only one there who experiences the problem (and, coincidentally, he's the only on there running Office 2013 on Windows 8.1). The network itself does not appear to be a problem, the clients and the Exchange server are bascially connected to the same switch. The issue seems to be limited to machines running Windows 8.1 and Outlook 2013. Now, a couple of users are complaining that their Outlook 2013 will randomly get loose its connection to the Exchange server, and the only 'solution' seems to be closing and restarting Outlook. (The Exchange server is running Exchage 2007 SP3, in case it matters). In the process, the new systems also got an upgrade to Office 2013.
Recently, we upgraded a bunch of desktop computer and laptops to phase out WinXP, either upgrading them to Windows 8.1 if the hardware was capable of running it, or replacing them altogether.
