今天要用Jmeter测试服务器性能，发现GUI界面总是有warning提示：
WARNING: Could not open/create prefs root node Software\JavaSoft\Prefs at root 0x80000002. Windows RegCreateKeyEx(...) returned error code 5.
在网上搜了搜，发现是Jmeter需要写注册表。
Problem(Abstract)
After running a clemb command under Windows 7 with Modeler 14.1 the following error is produced:
java.util.prefs.WindowsPreferences <init>
WARNING: Could not open/create prefs root node Software\JavaSoft\Prefs
at root 0x80000002. Windows RegCreateKeyEx(...) returned error code 5.
Cause
The error occurs because java.util.prefs.WindowsPreferences is trying to save information in HKEY_LOCAL_MACHINE\Software\JavaSoft\Prefs instead of under HKEY_CURRENT_USER\Software\JavaSoft\Prefs.
java.util.prefs.WindowsPreferences需要保存信息到HKEY_LOCAL_MACHINE\Software\JavaSoft\Prefs而不是HKEY_CURRENT_USER\Software\JavaSoft\Prefs。
Environment
Windows 7 64-bit
Resolving the problem
The work around is to login as the administrator and create the key HKEY_LOCAL_MACHINE\Software\JavaSoft\Prefs.
解决方案：
打开REGEDIT.EXE（真恨微软和其regedit.reg）。
然后创建HKEY_LOCAL_MACHINE\Software\JavaSoft\Prefs项
右键单击权限，然后更改权限为完全许可即可。
虽然Jmeter不会保存任何东西到该项，仍会将信息保存到HKEY_LOCAL_MACHINE\Software\JavaSoft\Prefs。