I recently upgraded my TortiseSVN to 1.5. This usually requires a reboot for the changes to be worked into the explorer shell. Some say you can use task manager to kill explorer.exe and, while that works, here is the way to restart explorer SAFELY thus saving a reboot:
XP/2003: click on Start and select Shut Down. The Windows shut down dialog will appear. Next, while holding down the Control, Shift, and Alt keys click the Cancel button on the shut down dialog window. You can tell because you will loose your Start menu, task bar, system tray and desktop icons. Now, press Ctrl-Alt-Del to bring up the Windows task manager. Click File and select New Task (Run…). You want to start explorer.exe so type in explorer.exe to relaunch Windows Explorer.
Vista: click on Start and hold down the Control and Shift and right-click on a blank space in the Start menu. Choose Exit Explorer. Open the Task Manager (Ctrl+Shift+Esc), navigate to File->Run, enter "explorer.exe" to restart it.
I've yet to test this on Windows server 2008 but I would think it would. I've tested this and as expected, this works on on Windows 2008 server too – it make sense since they are both considered 'Windows 6'
Remote Desktop users: since you can't use Ctrl-Alt-Del use Ctrl-Alt-End instead.