Besides by Mac laptop I have a Windows desktop at home. Windows 7 is all in all quite a nice OS. However, after using Windows for a while, Windows seems to start degrading. Of course one solution is to reinstall Windows, but that's not exactly a clean solution. I wanted to know the source why Windows seems so slow. Better investigation seems the only problem is the File Explorer, especially when using the context menu/right clicking on a file.
This led me to think some third shell extension for the explorer might be the cause.
After some google'ing I found this nice article: slow right click. In the article a tool is listed: ShellExView. Using this tool you can disable any shell extension that's hooked in the explorer. I disabled all software not coming from Microsoft, and my Windows starting working smoothly again! Of course any overlay icons from for example TortoiseSVN don't work anymore, but that's the whole idea of  these shell extensions. Now I just have to shell extensions one by one to find out what's the actual cause of the slowness, but that's better then reinstalling windows.