Program to measure small changes in reaction-time

I need some advice on writing a program that will be used as part of a psychology experiment. The program will track small changes in reaction time. The experimental subject will be asked to solve a series of very simple math problems (such as "2x4=" or "3+5="). The answer is always a single digit. The program will determine the time between the presentation of the problem and the keystroke that answers it. (Typical reaction times are on the order of 200-300 milliseconds.)

I'm not a professional programmer, but about twenty years ago, I took some courses in PL/I, Pascal, BASIC, and APL. Before I invest the time in writing the program, I'd like to know whether I can get away with using a programming package that runs under Windows 7 (this would be the easiest approach for me), or whether I should be looking at a real-time operating system. I've encountered 开发者_运维百科conflicting opinions on this matter, and I was hoping to get some expert consensus.

I'm not relishing the thought of installing some sort of open-source Linux distribution that has real-time capabilities -- but if that's what it takes to get reliable data, then so be it.

Affect seems like it could save you the programming: http://ppw.kuleuven.be/leerpsy/affect4/index2.php. Concerning accuracy on a windows machine, read this.