I went to a client for a PC clean up last night.
I removed a load of start up programs but one issue I could not solve was that the windows magnifier always opened up and made using the screen difficult on start up.
In the end I had to Google the problem and to come up with the solution.
Go to All Programs — Go to Accessories — Go to Ease of Access — Go to Ease of Access Center — Click the blue link titled Make computer easier to see — UNCHECK turn on Magnifier — Click Apply and then exit… Restart computer and make sure that magnifier does not start upon startup.
You can also get to the configuration by typing ease of access in to the vista search bar.