Use PowerShell to determine which registered SQL Servers have the ENABLED GUEST user with HTML output.
Tasks:
  1. Extract the list of all registered SQL servers.
  2. Get a T-SQL script ready.
  3. Get the HTML and CSS style ready.
  4. Combine them in PowerShell.
In most cases, locating a user within a SQL server is rather simple. The new system table or the conventional system table can be used.
sysusers
sys.database_principals
However, the user's enabled or disabled status, which is only available through the table, is: sys.sysusers. Let's get right to the coding.

Error message:
Could not load file or assembly ‘Microsoft.SqlServer.Management.IntegrationServicesEnum, Culture=neutral, PublicKeyToken=89845dcd8080cc91’ or one of its dependencies. The parameter is incorrect. (Exception from HRESULT: 0x80070057 (E_INVALIDARG)) (mscorlib)