PURPOSE: To shorten the processing time of the execute form program without caring the executable environment of an execute form program by a user in a computer system which has mutually different environments on a network and shares an external storage device.

CONSTITUTION: A program starting means 12a obtains information on the executable environment of the execute form program 141 by using a file type acquiring means 11, logs in the computer system where the execute form program 141 can be executed by using the information and a remote log-in means 13, and calls a program starting means 12b at the log-in destination to execute the execute form program 141. Consequently, the user need not be aware of the executable environment of the execute form program 141 and the execute form program processing time can be shortened.