He is referring to the security setting - do you have security enabled? If yes, then delete the router from your available connections and then go through the process to re-add it (aka associate it).

Another path to try - is your home router also a Belkin Pre-N or something else? If it is different than what you connect to at home, then would check what wireless hardware the others' laptops have vs. your HP. If you have hardware they do not, then google that hardware, Belkin pre-N, and "cannot connect." I just searched on "Belkin Pre-N cannot connect" and there seems to be many reasons folks have trouble connecting to them. A lot of it has to do with different security settings and encryption.

Also, how many other people are already connected? Is there any type of maximum #/limit of allowed wireless connections set on the router?