Hard to say. Could you start with some information? Make/model of the modem and router, operating system and patch level in use, and the make/model of the two wireless computers and the wireless card they're using.
On a working and non-working computer, do this:
Open a DOS window and type:
IPCONFIG /ALL >C:\RESULT.TXT
Open C:\RESULT.TXT with Notepad and copy/paste the entire results here.
On a working and non-working computer, do this:
Open a DOS window and type:
IPCONFIG /ALL >C:\RESULT.TXT
Open C:\RESULT.TXT with Notepad and copy/paste the entire results here.
