Printer color profile onscreen display   

I am trying to use Photoshop to display my images with the same colors as 
they'll appear when I print them on my printer. I'm pretty new to color 
management, and the first time I did it, I simply followed instructions and 
everything worked great. I assigned my printer's ICC profile to the document 
in Photoshop, and it looked onscreen almost exactly like it did when printed.

Then, a few weeks later, I tried again, and although I'm following the same 
steps, the printout and the displayed images don't look the same any more.

I'm afraid I might have inadvertently changed some settings in Windows that 
are preventing the monitor from properly displaying the color. 

Does anyone know of any settings (services, startup programs, etc.) that 
Windows might be using to apply color profiles to my display? Feel free to 
share anything that you think might be remotely related.

I guess it's possible, although unlikely, since the computer is barely 2 
months old, that I need to re-calibrate the monitor. In that case, does 
anyone know any good (free or cheap preferred) software for calibrating 
monitors? 

Thanks!

date: Thu, 26 Jun 2008 18:31:01 -0700   author:   Chufflebean