Req Network Help

Hi

I have 3 pcs networked together 2 desktop & 1 laptop
The 2 desktop have win 98se the laptop has win xp.

They can all see each other they can all connect to the web etc....
i cant amend copy & paste anything to the laptop it says I don't have
permission.

Is there a setting in win xp, as im not familiar with win xp.

Thanks