networking problems

my windows 98 machine all of the sudden wont browse the internet or my network. it will connect through my dial-up service but then i cant go any where. same type of thing with my home network. i used to be able to send files using netmeeting now i cant and i cant use the ping command in my msdos prompt on eighter machines. it was all working fine before

any help would be great

Have you installed any new patches/changed any of your network settings recently? If so, that might be the case.