Quote: "Sounds miserible, but when you get 100-odd people relying on you for IT support both in work and at home, well it gets to be a pain in the ass."
Amen to that! I was very (over) generous with my time at my old job. I remember one time when I probably fixed at-least 7 or 8 computers with various issues over the span of a month. Keep in mind this was in the midst of a massive move of all our equipment to an off site data center, and on top of that we were migrating from a MS 2003 to 2008 R2 environment, so I was already at wits end. I always made a point to bring their computer home and work on it on my own time, however I never asked for much money(if any) because the problems were easily solved, even though I easily saved them loads of money had they brought it to a repair shop.
I specifically remember fixing one computer by doing a fresh install of Windows(After informing the person all the usual, did you make backups, you'll lose all your files, programs, etc.). Of course any IT guy has probably done a reformat/install of windows more times then they can count, and could probably do it in their sleep. Its a routine procedure, and aside from some weird disk errors, pretty much nothing can go wrong.
So this person comes into my office a month later and informs me their screen is no longer working, and that it
must be my fault since I worked on it. Apparently their "computer savy" friend told them that re-installing windows stresses the hard drive thus caused the screen to go out, somehow

. Naturally, It was all I could do not to laugh in this persons face. I told them, kindly of course, that their friend was misinformed, and that I would be glad to look at their screen, but
THIS time I
would be charging. They didn't take to that well and said that I would be hearing from them again. Must have gotton a second opinion from a more informed friend, becuase I haven't heard from them since
Now, I do not fix anyone's stuff at work, its unfortunate but the workplace is already a minefield, no need to over stress yourself and potentially create more chaos then their already is.
So, the best course of action is to humor your boss and put up some stuff to flair up your office, but still make yourself as unwelcoming a presence as possible. Otherwise, people can and WILL take advantage of you.