can't connect to internet with administrator but can with user acc

hi, i have a problem with connection to internet with administrator but i can
go to internet with user account. i start get that problem when i installed a
router.
i use windows xp 64 pro. normally i always use administrator and i have no
user account, but when i install new router, i can't connect to internet
anymore. so i created user account after try the solution that never be solf.
suddenly i could connect to internet with user account, but a lot of program
i can't used (share).
when i installed the router, i followed all step as it writen in router's
guide mode.

question :
1. how could i solf the problem connection ?
2. how could i use my game when i use my user account ? looks like the
windows don't give the permission to the user to use that program (game:
World of Warcraft).

ps: if someone answere this question, please explain to me in detail because
i don't know much about computer.

my compu :
Microsoft Windows XP Professional x64 Edition Version 2003 Service Pack 1
motherbord : ASUS A8N-SLI Deluxe.
Processors : AMD Athlon(tm) 64 Processor 3200+
1 RAM : NVIDIA GeForce 8800 GT, 1GIG.
router : D-Link r615.
Modem cable : Webstar