Since you told us nothing about what connection/router you have, I can only speculate, and quote a fact.
To use two NICs you need two accounts. If you have a hardwired connection, that broadband connection may, at the discression of your broadband (read wired) provider, give you instructions on bonding the two connections. Read again, two connections, two modems, and as such, you pay for two accesses.
Wireless? Ain't going to work.
How can I use both wireless adapters, so I can have a faster internet connection? I'm using Linksys pci wireless-N and Linksys USB wireless-N adapters. Both have an internet connection, but I don't know how to combine both signals into one stronger connection. Thank you! I'm using XP Pro.