wireless network slows down by adapter

[ioarvanit]

I have a home wireless network and till now i have been using my laptop and smartphone connecting, sharing and internet sharing with no problems.

Recently i brought a pc i had in my office which did not have a wireless adapter. I bought tp-link TLWN725N wireless adapter (http://www.tp-link.com/en/products/details/?model=TL-WN725N) and plug it to my pc to connect to the network.

Whenerver i connect to the networtk from my pc with this adapter everything slows down! And by everything i mean the whole wireless network from every device (pc, laptop, smartphone). I cant even reach the routers settings page whithout waiting for at least 2-3 minutes. When i plug the adapter out everything returns to normal for my laptop and smartphone.

I tried something else to check if the adapter is the only thing to blame. I installed it to my laptop and there seems to be no problem there. So the lethal combination is my adapter with the pc. The pc runs on windows 7, and my laptop on windows xp. I have installed the newest drivers for the adapter. Do you have any ideas?

Some more information about my systems:
wifi router: ZTE H108NS router provided by OTE
pc system summary:
PC Wizard 2012 Version 2.11
------------------------------------------------------------------------------------
Operating System: Windows 7 Ultimate Professional Media Center 6.01.7601 Service Pack 1
------------------------------------------------------------------------------------
<<< System Summary >>>
> Mainboard : MSI G41M4 (MS-7592)
> Chipset : Intel G41
> Processor : Intel Core 2 Quad Q8200 @ 2333 MHz
> Physical Memory : 4096 MB (2 x 2048 DDR2-SDRAM )
> Video Card : NVIDIA GeForce 9400 GT
> Hard Disk : Western Digital WD6400AAKS-22A7B2 ATA Device (640GB)
> CD-Rom Drive : DTSOFT Virtual CdRom Device
> DVD-Rom Drive : Optiarc DVD RW AD-7200S
> Network Card : Realtek Semiconductor RTL8168/8111 PCIe Gigabit Ethernet Adapter
> Operating System : Windows 7 Ultimate Professional Media Center 6.01.7601 Service Pack 1 (32-bit)
> DirectX : Version 11.00
> Windows Performance Index : 4.7 on 7.9

I would really apreciate any help as at which direction should i be looking for a solution

 

[fyrye]

It's possible you may have a virus on the PC, that when you connect to the network attempts to communicate/infect/detect the network, causing a bottleneck.

Run a virus scan using malwarebytes, personal anti-virus (AVG, COMODO, Norton, etc) and kaspersky TDSSKiller.

 

[ioarvanit]

It's possible you may have a virus on the PC, that when you connect to the network attempts to communicate/infect/detect the network, causing a bottleneck.

Run a virus scan using malwarebytes, personal anti-virus (AVG, COMODO, Norton, etc) and kaspersky TDSSKiller.

Thanks for your reply. I have already tried to exclude this possibility. I have run avg full scan and antimalware and nothing interesting found. Also when i had the pc connected to another router through ethernet cable i had no problem.

I have also shut down dropbox, google drive and every other program that demands internet. Now i have noticed this: The bottleneck happens only when i open a browser (any browser) from the pc and request a url. When i am just connected, network seems fine. When i request a url from the pc bottleneck happens...

 

[fyrye]

The browser may have an addon/extension, which browser are you using?
Try a different browser like FireFox or google chrome without importing settings.
It sounds like a DNS issue, what DNS Server is your PC using for the Wireless adapter?

Start Orb, Search cmd, press enter, type in ipconfig /all
Find the row that says DNS Servers
http://www.cyberciti.biz/faq/how-to-find-out-what-my-dns-servers-address-is/


Be sure to run malwarebytes as well as the AVG scan, the avg scan alone generally won't detect most things that malwarebytes will, as well as TDSSKiller which will detect rootkits that AVG or malwarebytes won't.

 

[ioarvanit]

The browser may have an addon/extension, which browser are you using?
Try a different browser like FireFox or google chrome without importing settings.
It sounds like a DNS issue, what DNS Server is your PC using for the Wireless adapter?

Start Orb, Search cmd, press enter, type in ipconfig /all
Find the row that says DNS Servers
http://www.cyberciti.biz/faq/how-to-find-out-what-my-dns-servers-address-is/


Be sure to run malwarebytes as well as the AVG scan, the avg scan alone generally won't detect most things that malwarebytes will, as well as TDSSKiller which will detect rootkits that AVG or malwarebytes won't.

The DNS server is the same as in the laptop 192.168.1.1 which is the routers address. I run tdsskiller and nothing was found. I tried to update the database of Malwarebytes but the same bottleneck to the whole network. I have now downloaded the updates from my laptop and transfered them to the pc by usb. Now i am running a full Malwarebytes scan and praying...

 

[ioarvanit]

Frustration again. I have scanned my pc with malwarebytes again and nothing. Still the same problems. Whenever any program from the pc request anything from the internet the network stalls. I have noticed that the transfer rate differs between the cards in the laptop and the tplink usb card in my pc. The laptop cards show 150mbps and the tplink 60mbps. Do you think this has something to do with the problem?

 

[fyrye]

It technically shouldn't since it doesn't affect the laptop when it is plugged into it. Does this affect your wired and wireless network or just wireless (asking again to confirm from your OP).

If you haven't already you can try to update the firmware for the router.
You should be able to update using the router's configuration settings, if not browse to the manufacturer's website and download the latest firmware.

 

[ioarvanit]

It technically shouldn't since it doesn't affect the laptop when it is plugged into it. Does this affect your wired and wireless network or just wireless (asking again to confirm from your OP).

If you haven't already you can try to update the firmware for the router.
You should be able to update using the router's configuration settings, if not browse to the manufacturer's website and download the latest firmware.

I have already updated the firmware of the router. When i plug in the other laptop to the router wired it works ok. So the problem is only in wireless.

 

[fyrye]

Taking a wild guess at this point as the issue is rather strange.
Enable Wireless AP isolation mode and disable QoS in the router if it is not already. See if it improves

Thinking the Windows XP and Windows 7 network may be conflicting somehow.

Some other things to attempt, try both wired if able and see if the issue persists while wired, as well does the issue persist when the PC is the only device on the wireless network?

 

[ioarvanit]

Taking a wild guess at this point as the issue is rather strange.
Enable Wireless AP isolation mode and disable QoS in the router if it is not already. See if it improves

Thinking the Windows XP and Windows 7 network may be conflicting somehow.

Some other things to attempt, try both wired if able and see if the issue persists while wired, as well does the issue persist when the PC is the only device on the wireless network?

I think we are getting somewhere now! I have disabled the QoS in the router and now i have some improvements. The laptops are working better (but still a bit slow specially for streaming video) and the pc has improved. It does not stall but it is still very slow.

I cant find th wireless AP isiolation mode in my router settings to change that too. What exaclty is AP isolation mode?

UPDATED: As time went by things got worst again. Speed in network fell and now i have slow speed for laptops and smartphone and stall for pc. PC connects-disconnects from network, delays to obtain ip and when it does it stalls again