Dell Laptops no longer load networking drivers

[AndyDE]

I have two Dell LapTops - both with Vista. They normally do not get used much - last time was December. Today when I turned them on neither WAN nor Wireless would work. I added a Wireless Dongle and that was exactly the same. If I ask to Update the drivers it says Driver software is up to date. Why BOTH machines? Why do I get same error with a dongle? If I switch off and back on it locates the drivers but there was an error initialising them.

 

[AndyDE]

MERGED QUESTION
Question from AndyDE : "Dell Network Drivers Will Not Load"

I apologise if I have posted this earlier, but I am a new user of Tom’s, and cannot seem to find what I thought I had posted.
I have two Dell Laptops – an Inspiron 1520 (Vista Home Premium), and an Inspiron 6400 (Vista Basic). Neither gets used terribly often – in both cases about a month or 6 weeks ago. When I turned them on BOTH would not connect to the Internet, either via WiFi or via Ethernet. Device Manager shows all network adaptors with a yellow triangle on all – on both machines – in all cases with the message “The device is not working properly because Windows cannot load the drivers”. If an attempt is made via Device Manager to Update Driver, message “The driver software is up to date” and it does not load it. Both machines have Broadcom 440X 10/100 with integral WiFi adaptor. A new copy of the driver was downloaded via dongle to the machines. When installed this apparently deleted the adapter and reinstalled. During the installation process the message “ Windows found driver software for your device but encountered an error while trying to install it. The system cannot find the file specified.” was received. If I delete the adapter manually and restart, the same result. This occurs whether I let it search for the file, or I direct it to where the Dell downloaded driver is put.
I then attached an entirely separate WiFi dongle. Following the instructions for the WiFi dongle resulted in the same error message, and Device Manager showing it as disabled.
The problem is exactly the same on both machines. Both definitely previously worked OK (the data they all use is on a networked drive) although it is interesting that there is no system restore point prior to today. There are four other machines all working on the same network (although none of these are Vista – range between XP and Windows 10).
I’m baffled – ideas?