I Want to Hack in to My Friends System Through his wifi router i am controlling

recently i went to his room i connected to his wifi network he gave me the password,i tried to open wifi control panel luckily he left with default username and password.

i opened the control panel started remote management on in his router so i can access his router from my system. i got access to his wifi router now

now i want to enter in to his system is it possible?

Target Router:Netgear N300 wireless router model JWNR2000v2

Target Operating System: windows 7

No Antivirus installed in his system he is using microsoft security essentials

i am out of his wifi range but if needed i can get within his wifi range

is there any way to enter his system