Windows 7 wireless range issue

Okay, here's the deal:

Had my Sony VAIO for years with Vista on and a b/g wireless card - never had an issue using the wireless signal from my bedroom.
I now have a new HP Envy running windows 7 and it connects just fine, so far as getting to the stairs. If I go any further away the connection drops out very quickly and will rapidly stop working altogether. Admittedly this sounds like a hardware issue but after reading a lot of windows 7 wireless problems all over the internet I decided to install Vista to see if it would work again.
Upon installing Vista everything worked from my bedroom perfectly, the signal was better than ever. However, when I installed windows 7 again I had the same issue until yesterday morning where for about 2 hours it connected to the wireless again from my bedroom and then cut out once more.

I really am at a loss as to what is going wrong here, I can't find anyone having the same issue as me and I've tried all sorts of changes in configuration of windows 7 ie: power management, ipv4/6, updated drivers, disabled homegroup and also changed security settings on the router to see if that works - still I have the problem.

I'm not brilliant with computing but know the basics quite well and so can do most things, therefore any advice/ideas as to what I can do to resolve this would be much appreciated!

Thanks, Matt.

 

What usually helps in such a situation is editing the advanced settings of all power- profiles so that those are set to no power-saving/max speed (for wireless LAN only), have you already done that?

 

I have my friend, everything is at max