Could you recommend any tools for testing performance of desktop applications running on MS Windows? I would like to verify the speed of application activities versus HW and OS configuration. I have to perform tests on several HW desktops and and Win7, Win8, XP.
For some performance testing you don't need a specific tool, only a well-designed test case set, a bunch of test suites which with some variables can be used on any type of operating system family.
When you design the test cases, you should take in consideration the application's requirements and non-functionalities:
You may need for some performance testing types some simple tools, but they are not very complicated. For a load testing for example you can even use the windows' build-in tool, the Task Manager, to monitor the processes' behavior. As Tom77 said in his comment, sometimes even a stopwatch is enough, but ensure you make notes in a table to compare them at the end, and you are testing the right functionality of the application.
I think, the key is the test cases' correctness and portability. For this I can suggest the Microsoft's Test Manager, if you are already a Windows user. It isn't the best tool, quite buggy, but it can be easily integrated with other Agile tools, such as Workbench and Visual Studio.