virtualbox.org

I installed Windows Server 2003 R2 Standard x64 in Virtualbox with 2GB Ram,20GB disk,Guest Additions and bridged adapter.But i don't have internet!
Any ideas?

No, not on that amount of info.

Once you have set the vm to bridged mode, debugging network problems in the guest are exactly the same as for any physical machine in the LAN. Do you have a DHCP server on the LAN? Is the vm getting its network config from DHCP?

Minimum information needed for assistance.