There are two types of files that may cause this to happen.
1. If you are running any applications that automatically update a file or monitor activity, the hard drive may spin up to either read or save. Such programs include anti-virus, backup, spell checkers, and compression software.
The application may also need to load in resources which were not loaded when it launched. The same could hold true for system software resources that become needed after the drive spins down.
2. Some Extensions and Control Panels may cause the hard drive to spin up. When running on battery power, use the Extensions Manager to turn off as many Extensions and Control Panels as possible. This may help to eliminate spurious background activity.
Article Change History:
03 Apr 1995 - Additional reasons for spin up documented.
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