Check your OS environment.

1) If you are using Windows 7 and Service Pack 1 is not installed:

Go to either of the following websites:

http://www.microsoft.com/ja-jp/download/details.aspx?id=5842 (Japanese)
http://www.microsoft.com/en-us/download/details.aspx?id=5842 (English)

Depending on your OS environment, download and install one of the following:

windows6.1-KB976932-X64.exe (for 64-bit OS)
windows6.1-KB976932-X86.exe (for 32-bit OS) (If it has already been installed, skip this step.)


2) After Service Pack 1 is installed:

Go to either of the following websites:

http://www.microsoft.com/ja-jp/download/details.aspx?id=30679 (Japanese)
http://www.microsoft.com/en-us/download/details.aspx?id=30679 (English)

Then, download and install either of the following files:

VSU4/vcredist_x86.exe (for 32-bit VOCALOID4 Editor for Cubase users)
VSU4/vcredist_x64.exe (64-bit VOCALOID4 Editor for Cubase users)


3) Use Windows Update to apply the latest patches.


4) Restart your computer.