Win 8 Wifi Problem ,,please, save my sanity !!!

so my laptop is Lenovo G580 20157 it's about 3 and a half months old
It runs windows 8 32bit
we have a Netgear DG834PN router
the router security setting is set to WPA-PSK+WPA2-PSK
Driver is Broadcom 802.11n ( I tried many versions to see if it was the problem)
the hotkeys are to the maximum .....the router is right across the room
my sister's laptop has no problem connecting to the wifi whatsoever she also runs windows 8
I tried the option refresh your PC without affecting your files
and just today I tried remove everything and reinstall windows
...............
so my problem is that .. sometimes the wifi doesn't connect and when i run diagnostics the problem that it gives me sometimes is ( default gateway unavailable or windows cann't connect to the hidden network N123 )
that's one
some other times , yes it takes time to connect but if for instance I'm downloading sth with IDM ,as soon as I get up from in front the laptop and just look at the screen from the side i see the speed declining and then it reaches 0 bytes and then the wifi itself disconnects ,, if in the middle of this process I sit down in front of the screen again the speed would go up .....
It's like it's playing with me

I'm not imagining it
I've tried setting the security on the pc to WPA-Personal & WPA2-personal both AES &TKIP ,,,,,,, problem persists
I've cleared the option of (allow the computer to turn off this device to save power)
In the power plan I've set the performance to maximum performance

I'm sorry for writing too much but I wrote everything I could think of

 

Wifi was working fine by the way for a bout 2 and a half months or so
and btw the wired connection is working fine although it's a little slow
the speed with the wifi is up and down sometimes it's working fine and other times it's slow and sometimes it disconnects while I'm browsing so the problem isn't actually restricted to me being in front of it or not

if anyone thinks I'm crazy rolleyes ........ I'm not I swear

 

I'm sorry another thing when it was working I used to go into another room and work from there and I would still have 4 hotkeys now If I went there , I don't find it in the available networks and even if it appeared for a moment it wouldn't connect and then it disappears again

 

Have you tried updating your drivers?

|MG| SlimDrivers 2.2.28413.22077 Download

 

I just tried that slimdrivers and it said that I already have the latest updates

 

well for starters my sister's laptop is Acer , she has Qualcomm Atheros AR5B97 wireless adaptor

no yellow marks in device manager but it has this title of Other devices with a question mark besides it ( but not yellow though ) under it there are 6 blutetooth peripheral device and all of them has this question mark
but as far as I can remember they have been there before my problem started and bluetooth is working fine btw

by security software do you mean like Antivirus and so ??
we both have windows defender ,, but yesterday I was trying to rule out the possibility that the problem is caused by a virus or any other malware so I downloaded Avast .......... and nothing came up btw

I just tried the safe mood with networking ,,,, the PC itself is working ok , the wifi connected after a while as usual but it's tooooo slow and still disconnects

and I have made a new discovery , I was doind sth and I took the laptop to right next to the router and guess what ??
It worked fine no disconnets and even when I wasn't in front of it it remained connected
soI used to sit at the table acroos the room from the adaptor so I changed the place where I sit just to the other end of the table and it works fine also :-D
but the problem of the network not appearing when I go to the other room still persists ........
could it be the adapter itself ?
And I knw that I talk and write alot so pardon me

 

Other devices?

Can you post a picture of what that is?

 

well I thought to say that after testing the router and the adapter , the problem was with the adapter ,,,, and since the customer service didn't take it since they didn't sense my problem or sth like that ......my brother in law bought me an external network adapter and the problem is no more