PeterIs Ramblings

Ok yet again this is one of those notes to myself blog entries that might help someone else with a problem of network performance with a virtual PC.

Unlike my friend Liam Westley who is now a MVP for virtualization after moving to windows 7 recently I decided that I'd just use the Virtual PC that comes with windows 7 rather than fighting with either Hyper-V or Installing the older Virtual Server family.

I've spent some time looking into a problem where when I uploaded to Windows 2003 server I had running in a VM the upload speed was terrifyingly slow (Using BITS as it happens but UNC connections weren't any better) from my laptop, downloads seem to be OK. Worse still other people who uploaded to the server got the kind of performance figures I was expecting to see.

Anyway turns out the problem is TCP task offloading this kb article 888750 at Microsoft covers how to turn off task offloading and somewhat explains the problem.

Basically you create a DWORD key called DisableTaskOffload in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters and set it to 1 then reboot your PC.

Visual studio 2010 has removed the prompt for a password when you use codesigning with a .pfx file. This means you'll often get this error message:

  C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1970,9): error MSB3325: Cannot import the following key file: mykey.pfx. The key file may be password protected. To correct this, try to import the certificate again or manually install the certificate to the Strong Name CSP with the following key container name:
VS_KEY_C0D0ACB5FAE2DFE3 [C:\Source\MyProject.csproj]
  C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1970,9): error MSB3321: Importing key file "mykey.pfx" was canceled. [C:\Source\MyProject.csproj]

This is down as a connect bug here https://connect.microsoft.com/VisualStudio/feedback/details/524792/importing-key-file-was-canceled?wa=wsignin1.0 and sadly no one gives the correct answer.

This is somewhat cryptic and doesn't actually tell you how to fix the problem. So here for future reference is the answer (obviously change the file name and key to match your error message) run it from the command line:

sn.exe -i mykey.pfx VS_KEY_C0D0ACB5FAE2DFE3

Hope this helps.

Just noticed that you use certmgr.exe for installation of pfx for ClickOnce deployment purposes