a problem with the wifi

I suggest looking over the manual for your router, specific instructions for this will be located there.
Wireless 150N Router - LW150
the manual can be found about halfway down the page at the link above.
It apparently has to do with the method of security that specific router uses.

Maguscreed said:

I suggest looking over the manual for your router, specific instructions for this will be located there.
Wireless 150N Router - LW150
the manual can be found about halfway down the page at the link above.
It apparently has to do with the method of security that specific router uses.

Yes.

I believe that you will need to disable IEEE 802.1x authentication. I remember how that is done in XP. I'm poking around trying to find how to do it in 7.

In the Network and Sharing Center, click the icon for your wireless network
Next, click "Wireless Properties"
Choose the "Security" tab
What is the "Security type" set to? On my network it is set to "Shared"

but my other laptop connected instantly there wasnt any problem .. and my laptops are on windows xp sp 2

This is kind of off topic, but Microsoft no longer supports XP SP2. You need to install SP3 in order to get security updates.