I assume you mean a Windows 2008 R2 server, as there's no such thing as a "Windows 7 Server". I also assume you're using a DHCP client and not ifconfig to configure the NIC in Linux, as ifconfig cannot be used to obtain addresses using DHCP.
If you're getting an address in a completely different scope, there must be more than one DHCP server on your network. You will need to shut down that second DHCP server, as the Windows DHCP service will actually stop serving clients if it detects the presence of another, non-authorized DHCP server.
Also, your scope looks rather odd. What netmask are you using?