Starting instance of host on server failed. / Could not create SSOSQL

Every now and then the BizTalk hosts won't start with the following message in the BizTalk Administration console:

Starting instance of host on server failed.
For help, click: http://go.microsoft.com/fwlink/?LinkId=47400&ProdName=Microsoft+BizTalk+Server+2009&ProdVer=3.8.368.0&EvtSrc=Microsoft.BizTalk.Administration.SnapIn.Properties.Errors&EvtID=HostInstance_UnmapServerHostInstanceFailed

ADDITIONAL INFORMATION:
Failed to start the BizTalk Host instance. Check the event log on the server "" for more details.
Internal error: "The dependency service or group failed to start." (WinMgmt)

The dependency that failed can usually be found by looking at the error message in the event log. Most likely you will find that the Enterprise Single Sign-On Service is unable to start with the following two messages:

Log Name: Application
Source: ENTSSO
Date: 2010-10-26 09:47:25
Event ID: 11047
Task Category: Enterprise Single Sign-On
Level: Error
Keywords: Classic
User: N/A
Computer:
Description:
Could not create SSOSQL. To fix the problem, reinstall SSO or try 'regasm SSOSQL.dll' from a Visual Studio command prompt.
Error Code: 0x80131700

Log Name: Application
Source: ENTSSO
Date: 2010-10-26 09:47:25
Event ID: 10503
Task Category: Enterprise Single Sign-On
Level: Error
Keywords: Classic
User: N/A
Computer:
Description:
The SSO service failed to start.
Error Code: 0x80131700

This can as the message describes most likely be fixed by registering the SSOSQL binary. What the message doesn't mention is that the version of regasm.exe that you have to run is different if you run 32 or 64 bit Windows.

For 32 bit OS:
C:\Windows\Microsoft.NET\Framework\v2.0.50727\RegAsm.exe "C:\Program Files\Common Files\Enterprise Single Sign-On\SSOSQL.dll"

For 64 bit OS:
C:\Windows\Microsoft.NET\Framework64\v2.0.50727\RegAsm.exe "C:\Program Files\Common Files\Enterprise Single Sign-On\SSOSQL.dll"

After registering the binary, the Enterprise SSO service can be started and subsequently also the BizTalk host instances.

BizTalk configuration error: Failed to connect to the SQL database 'SSODB'

Sometimes when configuring a fresh installation of BizTalk Server, the following error might appear during the configuration of the Enterprise SSO:

Failed to connect to the SQL database 'SSODB' on SQL Server ''. (SSO) Additional information: (0x80131700) (Win32)

Most interesting is that the error is due to a failure to connect when the configuration is meant to create the database in question.

I found a solution through this blogpost which while it is for Windows Vista and a bit different, still has the same solution as for the above problem. By some reason the Enterprise SSO is not correctly installed and by registering the SQL module and run the configuration tool again, it will work:

1. Start a Visual Studio command prompt.
2. run regasm "c:\Program Files\Common Files\Enterprise Single Sign-On\SSOSQL.dll"
3. Run the BizTalk Server configuration tool again