Improve Access to Trace Data
Applies to: 
SQL Server
SQL Server Profiler uses space in the temp directory to improve access to trace data. SQL Server Profiler requires at least 10 megabytes (MB) of free space. If free space drops below 10 MB while you are using SQL Server Profiler, all SQL Server Profiler functions stop.
When SQL Server Profiler uses space in the temp directory, this space usage may cause the temp directory to grow rapidly. To avoid file-growth problems, you can place the temp directory on a drive that is not a system drive by changing the value for the TEMP environment variable.
The following procedure describes how to change the value for the TEMP environment variable in most Microsoft Windows operating systems. For more information about setting environment variables, see your Windows operating system documentation.
To change the TEMP environment variable in Windows operating systems
On the Start menu, choose Control Panel, and then click System.
In the System Properties dialog box, click the Advanced tab, and then click Environment Variables.
Scroll down the list of System Variables, select the row that corresponds to the TEMP variable, and click Edit.
In the Edit System Variable dialog box, enter the path and name of the drive and directory where you want the temp directory to be located.
Click OK to save the change.