Hey. I've got a wireless range issue, and was wondering if anyone out there would know of any way to fix this...

I get my internet from an external building, and can only receive a minimal signal (one bar) where I have my computer. Is there any way (inexpensive) that I can boost the signal strength from the wireless router to my computer? (and no I can't move my computer into the other building)

I have provided a pic of my issue below...


Any help would be appreciated.