I upgraded to windows XP pro with my VGN-A617b laptop, since then I
cannot connect to my Netgear wireless router. I get connection
established , and excellent signal, but I cannot open any pages, I
cannot even ping the router. very frustrating

There are too many things that you have to check. First that your IP
is still assigned by DHCP. Second that you have Service Pack 2
installed on your newly upgrades XP pro installation. Third that you
have your security parameters set up correctly on your laptop
connection with the wireless router.

If all the above sounds like Chinese to you then you should find a
friend that knows how to set up XP with wireless routers!

You should check for a vayo driver for wireless (the last version) or
try install the intel Proset/Wireless tools which contains the drivers
for all centrino based laptop

This could be one of two problems that i have personally experienced.

Check the WEP / WPA key are correct as this can lead to a lack of data
transfer but allow you to establish a connection.

Also as mentioned make sure that all your IP addresses are in the same subnet.

It is possible that in doing minor security updates that windows
sockets layer has been 'confused' and it needs to be repaired by
modifing the registry, the easiest way to do this is with a third
party application called winsockxpfix.exe.
It is a small program that could potentially fix you error.
It is available here:
http://www.snapfiles.com/php/download.php?id=107303&a=7120710&tag=1445888&loc=2
downloading it putting it on a CD and then executing it from you
laptop 'may' resolve your problem.