OK gather you sorted the compressed issue, an annoying problem most graphics programs have is they are set to compress TGA's Irfanview being one that does.
Actually I think it's in that version there is actually a TGA save option in Microdem need to scroll down as its at the bottom if I remember correctly.
The output from Hog needs to be named mapfile.gnd not as in the tutorial, TS2009 upwards won't accept any other name.
The other major change from the tutorial is the height conversion from Feet to Metres, if you hadn't noticed its already in metres.