I agree that windows can be a bit useless sometimes but my job is maintaining a vast number of servers and processnig machines. I have a couple of NT4 boxes with over 3 years uptime and 2 win2k boxes that have gone over 2 years. These are webservers, database servers and one thats just for file storage.
I have used linux a bit and not had any problems with it, my 2 test ones have been up for a few months quite happily.
Windows is best doing dedicated tasks, if you start running too much on them and playing around (ie let software developers near them), then they can cheek you

Darren