Wireless between vista and xp

I have tried to read other problems like mine, but I get lost. BEGINNER HERE.
Anyways... I have a vista computer which I set up my wireless network on.
I used wpa security, but now my laptop that I use wireless, says I cannot connect to my network because I need a certificate.

I did a little research and found that my xp laptop doesn't support wpa, so I downloaded a driver from microsoft.com, but I am still unable to connect.

I can connect to my wireless without security, but with security..... Any security (WPA2,WPA,or WEP)... My laptop will not connect..... It says it need to verify a certificate.

What should I do?

Thank you ,
Kristy

 

Please supply the following info, exact make and models of the equipment please.

Make and model of the broadband modem.
Make and model of the router.
Connection type, wired or wireless.
If wireless, encryption used, (none, WEP, WPA, or WPA2)
Make/model of your computer.
Version and patch level of Windows on all affected machines, i.e. XP-Home (or XP-Pro), SP2, Vista, etc.

Also, please give an exact description of your problem symptoms, including the exact text of any error messages.




On any problem computer, I'd also like to see this:

Start, Run, CMD to open a command prompt:

Type the following command:

IPCONFIG /ALL

Right click in the command window and choose Select All, then hit Enter.
Paste the results in a message here.

If you are on a machine with no network connection, use a floppy, USB disk, or a CD-RW disk to transfer a text file with the information to allow pasting it here.