<p>I installed TortoiseHg (Mercurial) in my Vista 64-bit and the context menu is not showing up when I right click a file or folder. 
Is there any workaround for this problem?</p>

According to the
TortoiseHg FAQ
the context menus will work in 64-bit Vista
if you start a 32-bit instance of explorer by creating a shortcut
with the following settings (as suggested in the answer above):
```
```
Target: %windir%\syswow64\explorer.exe /separate 
Start In: %windir%\syswow64\
```
```