Disabling LAN internet access and using Wireless router

I am on a cabled LAN network with internet access. I can also access the internet through a different wireless router. When I am connected to the LAN by internet access is also through it. I would like to stay connected to the LAN network but at the same time have the internet access through the wireless. Is there a way to set this up?

One way would be to remove the Default gateway and DNS server ip addresses from the ipv4 properties of the ethernet card (LAN card). That'll disable internet access via LAN but leave your local file sharing and print sharing intact.

Thanks for the advise but I have checked and there is already no default gateway or DNS in the ipv4 properties.

Are you getting those from the router via DHCP (Obtain ip and dns automatically)?

Yes, that is correct.

See, either you can enter a static private ip and omit the dns servers and default gateway (if you dont know how to do that or what the ip's are ask the network admin) or you can manually disable/enable the LAN connection (network and sharing center- change adapter properties- right click on LAN connection- disable/enable or just yank out/ plug in the ethernet cable) per requirement.