Page 331 - DCAP103_Principle of operating system

Principles of Operating Systems

Notes The registry is fully available to the Win32 programmer. There are calls to create and delete keys,
look up values within keys, and more. Some of the more useful ones are listed in Figure 10.6.

Figure 10.6: Some of the Win32 API calls for Using the Registry

Win32 API function Description
RegCreateKeyEx Create a new registry key
RegDeleteKey Delete a registry key
RegOpenKeyEx Open a key to get a handle to it
RegEnumKeyEx Enumerate the subkeys subordinate to the key
of the handle
RegQueryValueEx Look up the data for a value within a key

When the system is turned off, most of the registry information (but not all, as discussed above)
is stored on the disk in files called hives. Most of them are in \winnt\system32\config. Because
their integrity is so critical to correct system functioning, when they are updated, backups are
made automatically and writes are done using atomic transactions to prevent corruption in the
event of system crash during the write. Loss of the registry requires reinstalling all software.

Self Assessment

Multiple choice questions:
1. .................... is a line of operating systems produced by Microsoft for use on personal
computers, business desktops, laptops and servers.
( a) Windows 95 (b) Windows 98
( c) Windows 2000 (d) Windows Me
2. Window 95 was released in .................... .
( a) August 1995 (b) June 1998
( c) April 2000 (d) May 2000
3. In the millennium year 2000, Microsoft brought out a minor revision to Windows 98 called
.................... .
( a) Windows 95 (b) Windows NT
( c) Windows 2000 (d) Windows Me
4. One thing that Windows 2000 does not have is .................... .
( a) Server (b) MS-DOS
( c) System32 (d) Windows NT
5. At the top level, the Windows 2000 registry has .................... keys, called root keys.

( a) 2 (b) 4
( c) 6 (d) 8

10.3 Summary

• Windows 2000 which includes Microsoft Operating Systems for desktop and laptop.
• PCs can be divided into three families, i.e. MS-DOS, Consumer Windows and Windows
NT.

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