Weak RF Signal

[gsalmon4]

Ive got a DSL-G604T router at home that connects to my laptop fine through wireless connection via a DWL-G630 in the laptop. But when i walk around the house a normall 3 bed semi the connection goes. Seems like I need to boost the signal. Theres nothing electronic that will spoil the link that i can see.

Can anyone help!!
Thanks