Wireless connection drops after 10-20 seconds on Acer Aspire V3-572-56T3 running Windows 8.1

I'm having major problems with connecting to the wireless network in the office. It sees the network, allows me to enter the security credentials, then connects (with confimed internet connectivity) but drops out after 10-20 seconds. I have tried the wireless network at a friend's house which worked ok without any interruptions, so it is definitely nothing wrong with the hardware. I'm using a brand new Acer Aspire V3-572-56T3 on Windows 8.1, with all the latest drivers/patches loaded and have tried fiddling with many of the advanced settings for the network adapter to no avail. I logged on to the router to ensure all settings, encryption standards, channels etc. were matching but the problem keeps persisting. This has been ongoing for two days now and is driving me insane as I really need to have wi-fi working in the office. Plugging an ethernet cable straight into the router works fine but it's not the ideal solution (and is posing an OH&S hazard as it is laying on the floor). Can somebody pleeeease help!!?

FYI I have run diagnostics several times & the one thing that stood out was this:

Diagnostics Information (Wireless Connectivity)
Association status: Fail 0x00038002
Association reason code: 0x00000002

Result of diagnosis: Problem found
Issue referred to: RNWF MSM Helper Class
Root cause: Windows could not connect to "ERICSSON"
You can try to connect again.

Result of diagnosis: Problem found

Root cause:
Wireless association to "ERICSSON" failed
A response was not received from the router or access point.

Detailed root cause:
Wireless association to this network failed. Windows did not receive any response from the wireless router or accesspoint.

Repair option:
Look for causes of low wireless signal quality
The signal is weak due to distance or interference.
Windows Help and Support can provide more information about this problem.