There are two options to get rid of this error in your userenv log:
1) Setting the following registry configuration:
Hive: HKCU
Path: Software\Microsoft\Windows NT\CurrentVersion\Winlogon
Key: ParseAutoexec
Value: 0 = autoexec.bat is not parsed
1 = autoexec.bat is parsed
2) Create an autoexec.bat in the root of your system drive.
echo “@echo off”>>c:\autoexec.bat