First problem: very recently, after booting up I receive an error saying that my ATI graphics driver is not installed. To fix this, I went to ATI's site and downloaded the .exe for my graphics card's drivers. I ran the .exe, but when the install is just about complete, my computer blue screens with a registry_error. Rebooting after this blue screen, however, has "fixed" the problem, ie my graphics driver is installed and computer seems to run fine.
Second problem: booting yesterday did not send me to the windows load screen. Dos told me that no NT loader was present. Powering down and rebooting seemed to fix that problem as well...
Today I booted with the same missing graphics driver error (4th time). Running the .exe still crashes with a registry error, but now when I reboot the graphics driver is still not installed.