IDE and Monitor FREEZE when I "send" from the monitor

Development Tools IDE 1.x
1

Hi!
For some reason, whenever I press send on the monitor with some text written, the IDE and Monitor freezes in windows 8.1 64-bit and I can't shut down the program.
Even without any arduino connected to the computer in any way, this still happens.

Any ideas? Would love some help, as I can't use the Arduino unless I fix this :confused:

Using Arduino UNO rev3
Windows 8.1 64-bit

The problem accoured when I was trying to get a bluetooth module working. I might have done something to the serial ports. Is there any way of resetting everything about the ports to default?

Thanks in advance!