Command Prompt closes instantly

I have two computers running Windows 7 x64. On both of them, whenever I try to open a command line program it closes after a fraction of a second. This happens when I use ipconfig, and hldsupdatetool. This only started happening recently, sometime in the last few weeks, and I have no idea why.

I am aware that I can use cmd and then type ipconfig, but this doesn't work for hldsupdatetool, and it takes much longer than just double clicking or typing ipconfig in the start menu search.

I used HouseCall to scan for viruses, but it didn't find any. Is there any way I can fix this so the ipconfig and other command prompt windows stay open?