installation beginning to fall apart

usually in xp my installation would last at least a year or two before it
started to either grind to a halt almost or start action strange, ok the
first installation of vista was scrubbed due to the fact that it was a poor
installation attempt for unknown reasons, then second installation went fine
except for the odd annoying fact it would go to the BSOD and the fact then
when i put an extra gig, its just not worth the hassle, now my shortcuts are
missing the proper icon, i.e. its gone to a blank one, and everytime i try
to copy a photo to the desktop it disappears

so tell me what i should do?

should i start about thinking upgrading my cpu and mobo and risk another
activation?

current mobo: asus p4v8x-x and the cpu is 3.0ghz ht 1mb cache and not dual
core