# System paths

An administrator can set the following system paths in Administration > Site administration > Server > System Paths.

Note: When setting the system paths on Windows systems, use of the 8.3 notation for the path and filename is preferred. So instead of entering c:\program files\path to aspell\aspell.exe, enter c:\progra~1\path~1\aspell.exe. Check the exact 8.3 path using the dir /x command at the prompt.

## Path to du

This binary file was used in Moodle 1.x to quickly look up the size of data directories. It is possible that some add-ons still use this functionality.

## Path to aspell

If PSpellSpell is selected as the spell engine for TinyMCE in Administration > Site administration > Plugins > Text editors > TinyMCE HTML editor then you must specify the correct path to access the aspell binary.

In addition, you MUST have aspell 0.50 or later installed on your server. On Unix/Linux systems use the which program to determine the path:

```[root@moodle ~]# which aspell
/usr/bin/aspell
```

In this example the path to enter is /usr/bin/aspell.

On a Windows system, download and install GNU aspell together with at least one dictionary and then use the search facility in Explorer to find the aspell.exe file. The path should look like:

```c:\program files\aspell\bin\aspell.exe
```

It can be best to install aspell in c:\aspell or use the 8.3 notation if you are installing in c:\program files so that the path looks like

```c:\progra~1\aspell\bin\aspell.exe
```

## Path to dot

Path to dot is for enabling image generation in profiling. The generated graphs are really useful to see what each request does. To have profiling visible (and working), the xhprof extension must be installed in PHP.