Hi, This one is driving me totally nuts.

I have being trying to upload a file to www.virustotal.com (its a harmless exe I have since found out - DiskWipe.exe from diskwipe.org). Using IE8.

From Win 7 and Win 2008 R2 Datacenter (which I select to boot from vhd's) onto my main machine hardware, and also on another Win 7 PC elsewhere on my network, when I upload the file to virustotal.com it works perfectly. So, using my native NIC's everything is fine. Using another machine also perfect. Right.

OK, from my boot menu the default is my main development machine - the one I'm typing on now. This runs on the metal and has Hyper-V role and I have some guests. All guests are not running.

Amazingly, from my console (root partition to be exact) or any guest OS 2003 /XP / 2008 R2 etc. My upload to virustotal.com slows at 32% then HANGS at 38.something% & never finishes!!

Here is the kicker. I have another box (my main server) running Hyper-V on the metal and three live guests. Identical H/W to my main dev machine in another room. (Except OS is Datacenter - Mine is Enterprise). If I try and upload from its bare metal console or any guest this file to virustotal.com using IE8 it stops exactly in the same place!!

As for "steps I have tried etc." are kind-of blown out of the water as my server box is doing the precise same thing as the machine in my room here.

OK, comonalities: Mobo: Gigabyte GA-X58-UD5, 12GB Kingston RAM, Corei7 920 4 cores hyperthreading = 8 & Realtek RTL8168D/8111D Family PCI-E Gigabit Ethernet NIC's.

All 3 machines have this same motherboard - revision F11 Bios, all have 12GB RAM, all have the Realtek Nic's. All x64 by the way as I mentioned before I have a Win 7 box also with the UD5 m/Board, 12 GB RAM - bit of an overkill. :-)

All these machines when NOT running Hyper-V can upload this file. Perhaps you may like to try it on a Hyepr-v (2008 R2) yourselves with IE8 and the desktop experience is on. See if it works or fails for you. Root OS or any guest.

So, looking like its the NIC + Hyper-V = Cannot upload this file (any file I must add.) Realtek Nic is Ver 7.002.1125.2008. Using IE8

I see in the nic settings there are the usual parameters for Jumbo frames / Checksum offloading etc. several others. Should I fiddle with these?

I ran Netmon 3.3 in a guest and the TCP session halted as the upload failed. I suppose I could study that further. I dont have Netmon on the root partition machine (yet)!

All OS's fully patched - including todays defender files. My box running Office 2007 - but identical server in another room is not.

Also, if I fire up a VPN to a distant client and do the upload it works! Of course its a different network path.

Suggestions welcome please. If I left out anything important - please yell at me.

Many Thanks,