My guess is that the problem lies more with your connection. How are you connected with the internet? Can you bench that? How are you storing your DNS requests? I've never looked into how WinCE resolves this, but I assume do to the limited space there is zero back up and it must be resolved at router or ISP level each time. Are you behind a firewall that is blocking? Should you be pinging google's servers? If you do it a bunch most firewalls will drop connection to avoid Denial of Service attacks. If you have the opportunity, see if another laptop that has better specs can get better service from the same wireless access point. Remember too that Wifi is rated for various speeds, all of which are less than a hard connection. In general, I'd say review your connection first. For example, at my Lab in University, I have a T1 > speed connection, but at home ~53ms/ping.
Note: I don't believe that ping is an installed WinCE component standard, but it is easy enough to install regardless. Out of curiosity, what software / version are you using?