internet issues

i have a Wireless-G MIMO Performance* Broadband Router and Access Point with High Gain Antenna and continue to have issues with the wireless connection to my hp notebook. whenever my sister who has a dell computer gets on her computer and connects to the internet i am unable to connect to the internet, however, if she logs off and i log into the internet first i am able to access it whether she is online or not. this process continues for about a week and a half to two weeks and then i am unable to connect to my connection no matter which members of my family are on. could this be a hardware compatability problem or could it be a problem with having multiple users accessing the router daily? is it perhaps time that i invested in a new router and is there one that is better than another in consideration to having multiple brands of laptops?

 

You ISP may be seeing all of the pc and blocking you based on MAC. I would clone the MAC address of the PC used to setup the account into the router. That way the ISP will only see the single pc MAC no matter how many connects.

 

i will try that and see what happens.. if anyone else has any more ideas please comment