CentOS

Hello Guys,
I recently attempted to upgrade a kernel on my vps last night when something horribly went wrong. When I restarted the vps, I couldn't access putty, so when I went thru the VNC control panel thru the host I use, apparently somehow the network within the vps got completely messed up. I cant even ping google.com... I am desperate need of help, I am not sure where to start. Please help.

You upgraded your kernel from what to what?
Can you select the older kernel at boot?