Greetings,I've been running Windows Vista home premium on my PC for a long time, and I'm connected to the internet through an ADSL line.The PC is connected to the ADSL router through a direct ethernet connection, and every thing was going great.Recently, my internet connection started to suffer a terrible performance degradation, It's not something related to connection speed, but it was that when I open a web page, the HTML page is displayed but most of the images and other content are not downloaded, sometimes the entire page is not loaded, and the problem occurs on all the web browsers I used.Using an HTTP monitoring tool, I found out that the requests for the images end with error or time out status.I suspected the physical connection, so I changed the ADSL splitter, and fixed the phone wires, but the problem still occurs.I have Virtual PC installed on my Vista OS, when I run a Windows XP image on Virtual PC, I find that the internet connection performs very well in the virtually running OS, and the web pages are fully displayed within the usual time periods, meaning that the problem is not of the ADSL router, the network card driver nor the ADSL line.I also tried to connect to the router through USB, but the problem still there.I have Windows Updates turned on, and I blindly install the downloaded updates, which makes me suspect that one of these updates has corrupted my tcp/ip protocol stack driver.I feel that the problem is caused of some kind of restrictions made on the number of concurrent tcp connections a browser can made, or else why direct file download works with the full 256 Kbps line speed while web page loading (which involves many connections) suffers bad performance?I think that the problem is complicated, and I don't remember which update may be causing the problem, I just hope that one of the forum members will provide me with a point to start from because I have no idea what's causing this behaviour.Thank you for your help.

Hi, Before moving on, I suggest updating your anti-virus program to the latest version and perform a virus scan first. If you do not own an antivirus program, Microsoft offers Windows Live OneCare safety scanner. To download a free trial version of Windows Live OneCare, visit the following Microsoft Web site: http://onecare.live.com/standard/en-us/default.htm If the issue persists, please try to disable Receive Window Auto-Tuning to troubleshoot this issue. 1.Open up an elevated command prompt. 2.Enter the following command to disable auto-tuning netsh interface tcp set global autotuninglevel=disabled 3.Reboot the computer to test this issue again. If you found that this doesnt fix your problem, you can turn it back on. 1.Open up an elevated command prompt. 2.Enter the following command to enable auto-tuning netsh interface tcp set global autotuninglevel=normal Then, please try to take a clean boot to confirm whether this is a software conflict problem. Test issue in Clean Boot ============================= 1. Click Start, type "MSCONFIG" (without the quotations) in the Search Bar and Press "Enter" to start the System Configuration Utility. 2. Click the "Services" tab, check the "Hide All Microsoft Services" box and click "Disable All" (if it is not gray). 3. Click the "Startup" tab, click "Disable All" and click "OK". 4. Restart the computer and test the issue. Note: Clean Boot is a troubleshooting step. If some programs have been disabled, we can re-enable them later. If you see the System Configuration Utility, check the box of "Don't show this message" and then click "OK". Please monitor the system in the Clean Boot environment. If the problem does not occur, it indicates that the problem is related to one application or service we have disabled. You may use the MSCONFIG tool again to re-enable the disabled item one by one to find out the culprit. Hope it helps.

I disabled IP6 and the network topology discovery protocols, and this made Internet Explorer to work well, while Opera and Firefox still suffer.I uninstalled Firefox, cleared its installation folder, so that I get rid of all the extensions and plugins, then I reinstalled to find that the problem is resolved.