Greetings, folks. One of our clients has a PC that will only allow the user to send 3 emails before it locks up. "Outlook.exe" is still running in task manager and cannot be killed. The PC has to be shut down hard (holding the power button in) as it hangs during a soft restart.
The PC is a Lenovo E540 running Windows 7 Pro 64-bit. Office is Office 2013 Home and Business with Outlook attached to an Office 365 account. All software up to date.
If we start Outlook in Safe mode (just Outlook, not Windows) then everything works fine. I can send dozens of test emails with no problems at all.
So here's what I've done.
Disabled Hardware Acceleration, including adding an entry in the Registry (HKCU/Software/Microsoft/Office/15/Graphics/DisableHardwareAcceleration=1) Effect: no change.
Disabled all add-ins. Effect: no change.
Uninstalled the antivirus client (Trend Micro). Effect: no change.
Desktop Session Manager service disabled. Effect: this caused a number of problems--I couldn't even get into Outlook--so I re-enabled it.
I removed some components from a previous version of Office (2010) but since that is only Visio, I didn't remove everything. Effect: no change.
Office repair (both quick and web-based) from Control Panel. (Pro tip: the web-based one is basically a re-install, so have your code ready.) Effect: no change.
The user's mailbox file is located on a network drive, but since everyone's is, I don't think this is the source of the problem. It's also not a large file.
If I create a new profile, things will work fine for a few weeks but the problem will reappear.
I am open (and grateful) for any and all suggestions, but do note the steps I've already taken. I'd prefer not to rebuild the entire system from the ground up, since that doesn't tell me what was wrong to start with.
From searching on the web, this is a common problem and no one seems to have a solid solution (at least, none of the things I've tried have worked).