Update installation.md

faq/installation.md

@@ -7,11 +7,19 @@ redirect_from:
 
 # Installation and setting up the path
 
-In general you should *not* add FieldTrip with all subdirectories to your path. There are a number of external toolboxes in `fieldtrip/external` that are irrelevant for most users, and even can cause some problems if they overlap with other (custom) toolboxes on your path. Furthermore, there are some functions for backward compatibility in `fieldtrip/compat`, which should *only* be added to your path in case you use the corresponding old MATLAB release.
+In general you should *not* add FieldTrip with all subdirectories to your path. In other words, don't use a command such as ```addpath(genpath(<path_to_fieldtrip>))```, nor use MATLAB's graphical user interface to set the path. There are a number of external toolboxes in `fieldtrip/external` that are irrelevant for most users, and even can cause some problems if they overlap with other (custom) toolboxes on your path. Furthermore, there are some functions for backward compatibility in `fieldtrip/compat`, which should *only* be added to your path in case you use the corresponding old MATLAB release.
+
+## Step 0
+
+As a preliminary, you may want to consider to restore the default MATLAB path. This is done by
+
+    restoredefaultpath
+
+This ensures that no trailing instances of potentially clashing functions are present on the path, including parts of the FieldTrip code that are shipped with other toolboxes such as SPM or EEGLAB.
 
 ## Step 1
 
-You should do
+Next, you should do
 
     addpath <path_to_fieldtrip>