The TEMP/TMP variable appears to point to an invalid or inappropriate folder
[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at http://go.microsoft.com/fwlink/?linkid=34707.]
Topic Last Modified: 2010-05-25
On a non-clustered Exchange Server computer, the Microsoft® Exchange Server Analyzer Tool reads the following registry entries to determine the value for the TEMP and TMP environment variables:
The Microsoft Exchange Information Store service uses the TEMP and TMP folders as temporary storage during various operations, such as message conversion and mailbox move operations. On a non-clustered Exchange server, the Microsoft Exchange Information Store service uses the SYSTEM (for example, Local System), which uses a default environment variable setting of %Systemroot%\Temp for both TEMP and TMP. If either one or both of the Exchange Server's TEMP or TMP environment variables begin with %SYSTEMROOT, a warning is displayed.
The TEMP and TMP environment variables are used to designate which folders in the file system (which path) should be used by applications that require a temporary workspace. TEMP is typically used by applications, such as Microsoft Exchange. TMP is typically used by development tools, such as Microsoft Visual C++®. The path for each variable is usually relative to the security context of the application or tool.
When the Exchange Server Analyzer is run against an Exchange Virtual Server in a Microsoft Windows Server™ 2003 cluster, it does not read the HKLM registry tree. Instead, it reads the following registry entries:
HKEY_USERS\<Cluster service account SID>\Environment\TEMP
HKEY_USERS\<Cluster service account SID>\Environment\TMP
Exchange Virtual Servers running in a Windows Server 2003 cluster use the environment variable settings for the Cluster Service account, which runs under the context of a specific user security principle. For user accounts, the default environment variable for TEMP and TMP is set to %Userprofile%\temp. If either or both of the Exchange Virtual Server's TEMP or TMP environment variables begin with %SYSTEMROOT, a warning is displayed.
For optimal performance, we recommend that you do not use the disk containing the operating system for the TEMP and TMP folders used by Exchange. In addition, you should make sure that these environment variables are set to paths on a fast disk or disk subsystem, such as a RAID 0+1 spindle set. We also recommend that you do not use the disk containing the operating system for the TEMP and TMP folders that are used by Exchange or by Exchange Virtual Servers.
To correct this warning
Log on to the Exchange server computer with an account that has administrative rights.
Right-click My Computer, and then click Properties.
Click the Advanced tab.
Click the Environment Variables button.
In the System variables area, select TEMP, and then click the Edit button.
In the Variable value field, enter the new path for the TEMP environment variable, and then click OK.
In the System variables area, select TMP, and then click the Edit button.
In the Variable value field, enter the new path for the TMP environment variable, and then click OK.
Click OK two times to close the Environment Variables dialog box and the System Properties dialog box.
Restart the node to apply the change.
For more information about how to change the TEMP/TMP environment variables on a clustered Exchange server, see Cluster TEMP/TMP path is on the same drive as the system partition.