Use WGR614v7 with wireless adapter

My home is a two-story house. I have the main desktop/modem/WAP set-up on the bottom floor. When I am using a laptop in the upstairs room at the opposite end of the house, the signal strength is weak and fades in and out. I would like to know if I can use a Netgear WGR614 v7 wireless router and a Linksys dual-band wireless-N gaming and video adapter to set-up a WAP in the upstairs room. And if so, will this help with the signal strength at the opposite end of the house from the first WAP?