MS license agreements require me to allow MS access to my system?

While I am no lawyer, I, too, am of the opinion that the EULA you must agree to in order to install the service pack gives Microsoft the right to update your system for you. (I don't know what you mean by "do to my systems what I work quite hard at preventing." I'm assuming you mean breach security.)

While some may argue automatic, unattended, no permission required update by the developer of the application is a good thing, I disagree. Microsoft doesn't always get its fixes correct the right time (read: they may break something else). And besides, no fix should be applied without an evaluation of whether it is suitable for a particular machine. I would argue that MS does not have the information they would need to make that decision. I also believe this invades privacy.

While I may be leasing the operating system software from Microsoft, I own the computer, the data I have worked to put on it, and I use other software. I do not agree that MS has any right to access that without my permission.

Finally, those of you who work for hospitals, insurance companies, doctors offices and other facilities that have to prove compliance with HIPAA (the Health Insurance Portability and Accountability Act), you must be able to show that your systems protect patient information. How can you do that if MS has the right to invade your systems anytime they choose?