When I try to launch my Android Virtual Device, I get the following error.
Files\Android\android-sdk-windows\tools/emulator-arm.exe.
Hint: use '@foo' to launch a virtual device named 'foo'.
Please use -help for more information.
I have been using the emulator for months, and I just downloaded new updates from SDK/AVD Manager.
This problem is caused by blank spaces in the path you setup in the Android SDK. The solution is that you should move the folder of the Android SDK to a place without spaces, in your case:
E:\andriod-sdk-windows
or
D:\abc\xyz\android-sdk-windows
Please refer to the Stack Overflow post Starting the Android emulator in SDK tools, revision 12 for a solution. It did not come up in the search, but it did correct my problem. The space in the path name (PROGRAM FILES) seems to be causing the problem. I took the renaming suggestion to change the path name to PROGRA~1, and my problem was resolved.
It looks like someone already reported this problem, Issue 18317: Emulator in R12 doesn't properly invoke emulator-arm.exe if the install path as a space in it
... to summarize:
Yes, there will be a fix. We're working on it.
The primary workaround is install in a path with no spaces, e.g. c:\android.
If that's not a choice, the second workaround right now is to use the "short path" Windows notation, e.g. "C:\PROGRA~1" either on command lines or in the Eclipse preferences. Remember that the number might change depending on your directories; you can use "dir /X c:\" in cmd.exe to see the exact short path for a given directory.
We'll have to wait for their fix but in the meantime we can just remove the spaces in the Android installation directory.
In Eclipse go to Windows -> Preferences -> Android and in your SDK location replace C:\Program Files\android-sdk-windows with C:\PROGRA~1\android-sdk-windows
If you want to run the emulator only without eclipse you'll need to create a .bat file with the SDK short path:
for 32 bits machines: C:\PROGRA~1\Android\android-sdk\SDK Manager.exe
for 64 bits machines: C:\PROGRA~2\Android\android-sdk\SDK Manager.exe
来源：https://stackoverflow.com/questions/6629273/android-emulator-invalid-command-line-parameter