Windows Vista games running in software rendering mode

I am having the same problem as others purchasing a brand new system and
32-bit Vista OS in that the standard games that came with Vista are running
in software rendering mode, which results in them playing extremely slow (eg
moving a card in solitaire takes 1-2 seconds). The system also identifies a
base number of 1.0 for games, and requires 2.0 to play them adequately.

My systems specs are:
Intel E7200 2.53 GHz
500GB HD
512 MB Nvidia 8800
3BG DDR2 RAM

My system is only 2 weeks old, and this is really frustrating because the
scores for everything else the system does are at least 5.4.

Can anybody assist with how I can change the system to not run in software
rendering mode, or with any other suggestions.

Thanks in advance

Susan