.sys file

.com file

.cpl file

.pmg file

Only excel data

Only word data

Only PDF data

All data

Correction for programming incompatibilities

To protect from virus

It update only BIOS

To increase secondary memory

It is a collection of system program

It is a collection of hardware

Operating system is a application program

It is a driver

Process management

Hard disk management

RAM management

BIOS management