counterstrike source error in xp64 bit

[v8killaz]

so i just installed it and now i get an error right when i run it,
says

engine error-memory less than 128mb!!!-1900544

notice i have 4 gig or ram

any fix for this
or is this not going to run on 64 bit xp

 

[joeten]

what graphics are you using onboard or card

 

[v8killaz]

fixed