If you try to install the new vSphere5.5 C# Client to WindowsXP/Windows 2003, you will receive warning during the installation of possible problems. The problems is caused by the lack of support for some SSL ciphers on Windows XP and Windows Server 2003. Although the install will succeed and you’ll be able to connect to vSphere5.1 (and older) ESX hosts, if you attempt to connect to a vSphere5.5 host then you will receive this error message:

An unknown connection error occurred. (The Client could not send a complete request to the server. (The underlying connection was closed: An unexpected error occurred on a send.

The actual error looks like this:

Screen Shot 2013-10-19 at 12.56.28

There is a fix but only for Windows 2003 and WindowsXP 64-bit. This means Windows 2003 and XP 32-bit clients cannot use the ye olde vSphere Client. That’s was my situation so the fix wouldn’t install for me…

The link for the fix is below. It’s one of those where you have to supply an email, and then they email you a link to the hotfix. I’m assuming that’s so Microsoft and track and trace those people who need the fix.

http://support.microsoft.com/kb/948963

It’s also worth mentioning that the vSphere Client no longer installs to a Windows system running the Domain Controller role:

Screen Shot 2013-10-19 at 18.33.41