So the OS can't be used with other comps.
I still think it's a good deal. I was going to build a computer for my dad. I had a day long argument with him about not getting a dell. He won in the end because I couldn't come near dells price and all he was going to do with it was word processing/internet stuff. No games, photoshop, or anything like that.
cheapest 19" LCD on newegg ~ $230 + $185= $415 for the P4 and the monitor on newegg.
So an extra $100 or so for a fully fuctional computer is not bad, just keep in mind that many of the computers components are not of good quality and many upgrade options might not be possible such as a good graphics card (due to a weak PSU).