Unable to connect to internet or e mails

Hi
I am unable to connect to the internet (firefox) or to my my mail (microsoft outlook)----but I can connect to skype. My operating system is windows xp

I get error codes 80072ee7 and 0x800cc0d

I have been through all the settings with my isp and everything is correct

There are 3 other computers on the network and all working
I connected my computer to another station and still get same problem

It all started after an automatic download of windows service pack 3 (I think)

Please e mail me gleeda.icecream@gmail.com

Thanks

Avi Hinson