When your computer starts push F8 and select safe mode and see if that help speed up your boot time.
Try doing a restore at a point before the video card install and see if that helps. There may still be part of the video card driver hiding on your system. Did you switch from a Geforce to an ATI or the other way around? I had a big slow down when I switched from one brand to the other.I had to go into safe mode and uninstall/reinstall the video drivers.
How full is your hard drive? A drive that's getting full will slow things up.

99 Contour Sport SE MTX KKM filter, B&M shifter No res, BAT kit Green car silver hood (because silver is faster)