So in my house at the moment, my modem is running into a Belkin G+ router. We have a 2 story house and I sleep upstairs. My sister is also upstairs and her laptop picks up the internet... Just.

I'm getting a new computer soon in my room and I want Wireless-N. I know wireless-N has more range/speed than G, but does this depend on the router?

For example, will I be able to have faster/more stable internet than my sister because of the wireless-N card, or will I have to upgrade the router to an N series as well?

For your wireless-N card on your new computer to work in N mode, your router need to support N as well. Or else it will be running at G as well.

However, you should still be able to pick up the network better since your card has a better power to take in the signals better. However, as faulty.lee stated, it will still run in Wireless-G mode.

xboxrulz

For the 802.11n wireless card to fully utilise the 802.11n networking standard, you should upgrade to a wireless 802.11n router. If your sister is still using a 802.11g wireless card, you should ensure that the new 802.11n wireless router is backwards compatible with the wireless 802.11g standard, unless you wish to use your old 802.11g router as a wireless access point. I suggest you buy a wireless 802.11n router with two operating frequencies i.e. 2.4GHz and 5GHz.

Given the expense of replaqcing the router you may also be able to purchase better antenae for the existing router or possibly place a signal booster on the second floor of your residence.