不管你将 IntelliJ 装在什么地方，它都会在 C 盘的用户目录下创建 .IntelliJIdeaXX 目录，而且这个目录会随着时间增长到几个 G 那么大。这对于 C 盘小得可怜的人来说确实是个问题。不用怕，这里介绍一个将 .IntelliJIdeaXX 目录移到其他分区的办法。
我的 IntelliJ 装在 D:\Program Files\JetBrains\IntelliJ IDEA 8.1 目录下。我是这么做的：
1、首先在 D:\Program Files\JetBrains\ 下创建一个文件夹：IdeaConfig，用来存放所有的 IntelliJ 配置。
2、然后打开 D:\Program Files\JetBrains\IntelliJ IDEA 8.1\bin\idea.properties。
3、将所有的 ${user.home} 替换为 D:/Program Files/JetBrains/IdeaConfig （注意斜杠的方向）
4、保存 idea.properties
5、打开 C:\Documents and Settings\XXX 目录，把 .IntelliJIdea8x 和 .IntelliJIdea80 两个目录移动到 IdeaConfig 目录下。
这样你就可以启动 IntelliJ，而且以后也不会再占用 C 盘空间了。
【转自】：http://blog.csdn.net/YidingHe/article/details/4061251
# Use ${idea.home} macro to specify location relative to IDE installation home.
# Use ${xxx} where xxx is any Java property (including defined in previous lines of this file) to refer to its value.
# Note for Windows users: please make sure you're using forward slashes (e.g. c:/idea/system).
#---------------------------------------------------------------------
# Uncomment this option if you want to customize path to IDE config folder. Make sure you're using forward slashes.
#---------------------------------------------------------------------
idea.config.path=D:/idea_config/.IntelliJIdea13/config
#---------------------------------------------------------------------
# Uncomment this option if you want to customize path to IDE system folder. Make sure you're using forward slashes.
#---------------------------------------------------------------------
idea.system.path=D:/idea_config/.IntelliJIdea13/system
#---------------------------------------------------------------------
# Uncomment this option if you want to customize path to user installed plugins folder. Make sure you're using forward slashes.
#---------------------------------------------------------------------
idea.plugins.path=${idea.config.path}/plugins
#---------------------------------------------------------------------
# Uncomment this option if you want to customize path to IDE logs folder. Make sure you're using forward slashes.
#---------------------------------------------------------------------
idea.log.path=${idea.system.path}/log
#---------------------------------------------------------------------
# Maximum file size (kilobytes) IDE should provide code assistance for.
# The larger file is the slower its editor works and higher overall system memory requirements are
# if code assistance is enabled. Remove this property or set to very large number if you need
# code assistance for any files available regardless their size.
#---------------------------------------------------------------------
#idea.max.intellisense.filesize=2500
#---------------------------------------------------------------------
# This option controls console cyclic buffer: keeps the console output size not higher than the specified buffer size (Kb).
# Older lines are deleted. In order to disable cycle buffer use idea.cycle.buffer.size=disabled
#---------------------------------------------------------------------
idea.cycle.buffer.size=1024
#---------------------------------------------------------------------
# Configure if a special launcher should be used when running processes from within IDE.
# Using Launcher enables "soft exit" and "thread dump" features
#---------------------------------------------------------------------
idea.no.launcher=false
#---------------------------------------------------------------------
# To avoid too long classpath
#---------------------------------------------------------------------
idea.dynamic.classpath=false
#---------------------------------------------------------------------
# Uncomment this property to prevent IDE from throwing ProcessCanceledException when user activity
# detected. This option is only useful for plugin developers, while debugging PSI related activities
# performed in background error analysis thread.
# DO NOT UNCOMMENT THIS UNLESS YOU'RE DEBUGGING IDE ITSELF. Significant slowdowns and lockups will happen otherwise.
#---------------------------------------------------------------------
#idea.ProcessCanceledException=disabled
#---------------------------------------------------------------------
# There are two possible values of idea.popup.weight property: "heavy" and "medium".
# If you have WM configured as "Focus follows mouse with Auto Raise" then you have to
# set this property to "medium". It prevents problems with popup menus on some
# configurations.
#---------------------------------------------------------------------
idea.popup.weight=heavy
#---------------------------------------------------------------------
# Use default anti-aliasing in system, i.e. override value of "Settings|Editor|Appearance|Use anti-aliased font"
# option. May be useful when using Windows Remote Desktop Connection for instance.
#---------------------------------------------------------------------
idea.use.default.antialiasing.in.editor=false
#---------------------------------------------------------------------
# Disabling this property may lead to visual glitches like blinking and fail to repaint
# on certain display adapter cards.
#---------------------------------------------------------------------
sun.java2d.noddraw=true
#---------------------------------------------------------------------
# Removing this property may lead to editor performance degradation under Windows.
#---------------------------------------------------------------------
sun.java2d.d3d=false
#---------------------------------------------------------------------
# Workaround for slow scrolling in JDK6
#---------------------------------------------------------------------
swing.bufferPerWindow=false
#---------------------------------------------------------------------
# Removing this property may lead to editor performance degradation under X Window.
#---------------------------------------------------------------------
sun.java2d.pmoffscreen=false
#---------------------------------------------------------------------
# Workaround to avoid long hangs while accessing clipboard under Mac OS X.
#---------------------------------------------------------------------
#ide.mac.useNativeClipboard=True
#---------------------------------------------------------------------
# Maximum size (kilobytes) IDEA will load for showing past file contents -
# in Show Diff or when calculating Digest Diff
#---------------------------------------------------------------------
#idea.max.vcs.loaded.size.kb=20480
#---------------------------------------------------------------------
# IDEA can copy library .jar files to prevent their locking.
# By default this behavior is enabled on Windows and disabled on other platforms.
# Uncomment this property to override.
#---------------------------------------------------------------------
# idea.jars.nocopy=false
#---------------------------------------------------------------------
# The VM option value to be used to start a JVM in debug mode.
# Some JREs define it in a different way (-XXdebug in Oracle VM)
#---------------------------------------------------------------------
idea.xdebug.key=-Xdebug
#---------------------------------------------------------------------
# Switch into JMX 1.0 compatibility mode.
# Uncomment this option to be able to run IDEA using J2SDK 1.5+ while working
# with application servers (like WebLogic) running 1.4.
#---------------------------------------------------------------------
#jmx.serial.form=1.0
#-----------------------------------------------------------------------
# Change to 'enabled' if you want to receive instant visual notifications
# about fatal errors that happen to an IDE or plugins installed.
#-----------------------------------------------------------------------
idea.fatal.error.notification=disabled