"Could not find a part of the path" from MSBuild/CruiseControl.NET

This case turned out to be a no-brainer, but for my own (and others who may need it) later reference, here it is:
Scenario: I had set up a test environment for testing MSBuild targets run from CruiseControl.NET. The target I wanted to run was supposed to do simple file operations like copying and unzipping files to a specific disk letter, which in my test environment happened to be a subst to a folder on my local hard drive. Windows 7 64-bits with UAC (User Account Control) on was used, running CruiseControl.NET elevated to give it necessary privileges.
Problem: When running the MSBuild target itself, things worked like a dream. However, when running the target from CruiseControl.NET, it always grinded to a halt at the first attempt to copy/unzip data to my disk
Cause: This is the no-brainer: Since CruiseControl.NET ran with elevated privileges (i.e. started with "run as an administrator"), it did not see the substed drive I had set up from a non-elevated cmd window.
Solution: Simply start a cmd window elevated (run as administrator) and do the same subst from there, and voilla! - it works.

Administrator cannot change, delete or take ownership of file

Problem: It is well known that if a file is locked in Windows, an administrator can take control of the file by taking ownership of it, give himself permissions to write/delete it and then perform pretty much anything he needs to do with the file. Sometimes, however, you just receive an error message when you try to take ownership, even though you are an administrator, and even though the command prompt or Windows Explorer you are working from has been started by right-click - "Run as administrator"

Solution: Open Computer Management and open shared folders - open files. If the file in question is being held by someone that has opened the file over a fileshare, you first have to terminate their connection to the file before you can manipulate it. Of course, you should first make sure you are not disturbing any work they are doing on the file.

Cannot logon to newly installed SQL Server

Problem: After a fresh install of SQL Server 2008 R2 on a Windows 7 computer, where Windows user group BUILTIN\Administrators were given administrative rights, I was not able to log on to the database from Microsoft SQL Server Management Studio while logged on to Windows as a user who was a member of the Administrators group and thus should have been granted access. The error received was: Login failed for user 'COMPUTERNAME\user'. (Microsoft SQL Server, Error: 18456).

Solution: Turn off User Account Control, or if you prefer to leave it on, make sure you start SQL Server Management Studio as an administrator (right-click the icon and select Run as administrator).