My Surface is bonging gormlessly at me!

[Blu]

I have Outlook open, I am trying to close windows but every time I get the little arrow on the X in the red (or grey) box, it just makes a 'bong' or 'bing' noise.

It does it using both the trackpad and the touchscreen.

Anyone know why, or what I should do?

[Blu]

I have closed Outlook down using Task Manager and now it seems OK.

Had just crashed, I suppose.