Gaphics details

[MXJProductions]

for some reason I am having this issue, I can only run texture res at 64x64 if I jump up to 128x128 it crashes, And I would really like to go higher with the res but the game will not let me, I currently can run ground detail/tex full at 64x64 but I think that would be the reason for the ground quality is soo bad for me, its like it gets blurry and annoying. In this computer I have a radeon 4650, intel celeron CPU which isnt really that good, but My lappy is way better but, I prefer games on this one, as its bigger screen lol. any help would be great,

P,S I did not find any solutions searching. so I did try to look around before posting.