INSPIRON 1200/AT&T WIRELESS

Dell Inspiron 1200, XP Proffesional, AT&T wireless card that suddenly stopped functioning.  Com Mgr reads: No Device Detected.  Uninstalled the whole works, updated com mgr from att site. No good.  Replaced sim card and bought new wireless card (after sim didnt help).  Same issue.  NEC PMI Host Controller issue (in device manager) indicates insufficient resources to operate, need to disable another device.  But nothing physical changed with laptop prio to foulup.  AT&T stumped (?), says it's a computer issue.  Wireless USB port unit will work.