Have you considered either plugging in a Cat5 ethernet cable, to test and make sure there is nothing else wrong with your computer regarding networking issues? - I plugged in the ethernet cable that connects the router to the home computer and it works fine.
Have you recently re-installed the Operating System on the problem PC? - Not sure how to do this, help please?
Was the present wireless problem the reason why you decided you needed to reset your router? - The problem I had previously was "limited access" was coming up, my access to the internet changed every 5 minutes, so i reset the router and uninstalled the settings from my laptop.
If the wireless card is not showing up in device manager nowhere then it may have physically failed or depending on the type of adapter may have become dislodged. - I may check for the wireless card now.
Is the laptop still under warranty? Have you considered calling and or starting a trouble ticket with Acer Support? - yes, it is - the laptop is only 5 months max. old, but I'm not sure where the warranty is, and anyways I live in Ireland and it was purchased in England.
Link Removed due to 404 Error but since there are two options and you don't even know which one it is suppose to be and the fact that the OS doesn't even know that the physical device is present, it's not likely that a driver installation will have any impact on the problem. - I went onto the site of this and downloaded the Wireless LAN driver for Broadcom, but it made no difference.