Just to make sure: Did you install the most up to date drivers from Acer's support site, use a disc that came with it, or just use the Windows update drivers? If you didn't go to Acer's support site, I recommend going there and downloading the most recent drivers for the motherboard.
Hey, thanks for getting replying. Yeah all of the drivers are up to date, the majority from Acer support.
I've narrowed down the problem a little further - and my HDD is split into two paritions - C & D as it was set up in factory.
I've come to realise that the issues occur more prominently when you are transferring files to the D drive. When you are transfering to the C drive things are much more responsive, although not perfect I'd say.
I tried formating the D drive recently thinking it might need it especially after reformatting Windows and that the content on it was registered to the previous 'user' (i changed the computer name / user name).