Now be very careful here.  Click the little down arrow and select all the text you see.  Copy and paste it into Notepad so you can edit it easily.  It should look something like this:

-dc:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\DATA\master.mdf;-ec:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\LOG\ERRORLOG;-lc:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\DATA\mastlog.ldf

Edit the path for ERRORLOG to the new drive and folder.  The path must already be created so make sure you create this first.  Now paste your new paramaters back into the properties window and hit OK. Once you make the change, restart the service and immediately all new ERRORLOGs will be written at the new path.  Here is an example of moving the logs off to the E: drive in a folder called “SQL error logs”:

-dC:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\DATA\master.mdf;-eE:\SQL error logs\ERRORLOG;-lC:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\DATA\mastlog.ldf
 

How to move SQL error logs (ERRORLOG) to a different drive is a post from: JasonSamuel.com