Finding drivers for older equipment can be tricky. But they are out there. Be careful, though. A lot of sites posing as driver sites are come-ons for computer repair places, or worse - portals to trojans and viruses.
I recently bought a new wireless network card for my Hoary Old Dell Laptop - keeping it alive for another five years, at least (it runs remarkably fast, particularly after I re-installed Windows XP on it. A great portable net surfer and e-mail reader!).
I got the card on eBay for $5 from China. They sent it by mail. Got here in 10 days. Stranger things have happened.
I plugged it in and attached the internal antenna leads and powered up the laptop. It tried to self-install, but Windows could not find the right driver.
I went to the Dell website first and typed in my service number. No joy. They have a Broadcom driver, but it is not the Broadcom BCM4306 driver.
I searched online for "DELL DRIVERS" and "BROADCOM BCM4306 DRIVER" and found out that Broadcom no longer supports their legacy equipment (boo! hiss!).
I also found a lot of SPAM sites, advertising for computer repair. "Call our 1-800 number now, and we can fix your computer!" That is not a driver site.
A lot of other sites are just malware sites, trying to entice you to download the driver as an .exe file, or to download some "free compression software" to decompress the file - usually this is a malware package as well.
I finally found the driver on the HP site - they sold the Broadcom BCM3405 it with their older computers. I downloaded the driver, ran the install, and Voila! The computer now says, "Local wireless networks detected".
(Note: If you Google "HP DRIVERS" you will get a lot more SPAM sites for those 1-800 people. They use confusing URLs that look a lot like an official HP website. Don't be fooled. And don't click on a website that uses deceitful marketing practices like that. You know where the relationship is headed).
For $5, and about an hour of time, I have a usable laptop again. Maybe for years to come.
Some days you eat the Bear.