You can specify which directory you want to use as the server's temporary directory on Windows CE by setting the following value in the registry:
TempFolder is the name of the temporary directory you want to use. The server does one of the following:
use the specified directory if it exists.
attempt to create the specified directory if it does not already exist, as long as the parent directory already exists.
If the specified directory does not exist and cannot be created, the database server:
uses the \Temp directory if it exists.
attempts to create a \Temp directory if it does not already exist.
If the \Temp directory does not exist and cannot be created, the server uses the current directory.