Hexadecimal Display in debugging in VS 2003

Nalin, one of my colleague informed me that when he debugging in Visual Studio 2003, variable values are displaying in hexadecimal. Everybody confused. Some guys told it is problem with the mc, virus etc…
But guess what had happened? I found that there is no problem but in “Options -> Debugging -> General” he had enabled "Hexadecimal Display". He was telling that he didn’t do that. I also couldn’t think he would do that kinda thing.
By the way if he didn’t do that how it could be happened??? :)