need help with wireless router

i have finished installing a wireless DSL router to my
Desktop PC and my Laptop. i have noticed two problems
1:Whenever i try to download something, during the
download my download window freezes. It still moves and
everything, but it just doesnt download.
2:When i use my laptop on the internet (with the main PC
on and connected, of course), after i reboot or turn on
my PC again, the connection doesnt work. It works after i
turn off my router and modem and then turn them back on,
but thats irritating.
Please Help!!!