Hi Rick and Rajath
Thank you very much for all your help. Sorry for the delay in updating the thread but I did not have my computer.
I am not very technically minded and was finding it very difficult to understand the instructions, so I gave it to Paul who took it home for a few days to try and resolve this problem.
Here are his notes and screenshot that he gave me of what he tried:
"I uninstalled the WLAN Driver that was installed.
Rebooted the Laptop so I would have a clean slate to install the NEW Driver.
Upon Reboot (before I had a chance to install anything) It started installing WLAN Drivers from somewhere. I don’t know where!
I had moved the NEW Driver to the desktop in preparation for the install before I rebooted, so its possible that when the computer started and realised that there was no WLAN Driver installed it went searching and auto installed the file on the Desktop or possibly the USB stick that I left inserted which also had the NEW Driver on it.
However, after looking at the info on the now Installed Driver SEE JPEG, It’s my opinion that it installed the Original Driver from somewhere else on your Laptop."
As well as this he also sorted out the My Computer problem which had manifested itself last week - that of Not Responding every time I opened it. Paul said he googled the problem and found it was yet another wireless card conflict problem.
However, when I got the laptop back it was still the same (apart from the My Computer thing which was fixed) and I still couldn't connect to the internet.
Someone else in the office told me that it was possible to buy a wireless card that is like a USB stick and that would probably get around the problem. So I went to the local shop and for the bargain sum of 23 euros have bought one of these magic little yokes - hallelujiah - Internet!!!
Of course the fellas here are going crazy wanting to know WHY the dell card won't work as it should, but I don't care - I'm back in happy bunny land - I have trouble free wireless on my laptop and I don't care about the stupid Dell card any more.
I do thank you all for your time and trouble on my behalf and I hope this thread may help someone else
Kind regards, Michaela