1. BASIC SOFTWARE MAINTENANCE

2. a software product after delivery to correct faults, to improve performance or other attributes.
diagnosing and fixing errors, possibly ones found by users.
maintainability or reliability to prevent problems in the future.
modifying the system to cope with changes in the software environment.

4. is a diagnostic utility included in MS- DOS and Windows 9x.
SCANDISK
is a diagnostic utility included in MS- DOS and Windows 9x.
It checks and repairs file systems errors/bad sector on a disk drive. These errors often occur when Windows locks up and must be restarted. .

5. There are a number of reasons for the errors found inside a hard drive
There are a number of reasons for the errors found inside a hard drive. These include:
frequent system crashes
critical system applications that have been improperly closed
the existence of harmful programs such as viruses, trojans, etc.

6. ScanDisk included a more user-friendly interface than CHKDSK, more configuration options, and the ability to detect and (if possible) recover from physical errors on the disk.
ScanDisk would also repair crosslinked files.
In Windows 95 onwards, ScanDisk also had a graphical user interface.

7. How To Run Scandisk ?
All open programs be closed to help prevent any data loss and prevent any problems during scan.
Windows 95, 98, and ME users may even want to boot the computer into Safe Mode before running scandisk.
It is recommended that you run ScanDisk at least once per month.

8. STEP TO RUN SCANDISK Double-click My Computer
Highlight a local hard drive by clicking on it once
Right-click the highlighted local drive
Click Properties
Click the Tools tab and click Check Now to check the drive for errors
The computer will need to restart in order to run scandisk without getting interrupted

9. DISK DEFRAGMENTER
The process of consolidating fragmented files on computer's hard disk.
Fragmentation happens to a hard disk over time as you save, change, or delete files.
The changes that you save to a file are often stored at a location on the hard disk that's different from the original file.

10. When the file and the hard disk become fragmented, and your computer slows down as it has to look in many different places to open a file.

11. Disk Defragmenter is a tool that rearranges the data on your hard disk and reunites fragmented files so your computer can run more efficiently.
In this version of Windows, Disk Defragmenter runs on a schedule so you don't have to remember to run it, although you can still run it manually or change the schedule it uses.

13. VIRUS SCAN
anti-virus software is software used to prevent, detect and remove malware, such as: computer viruses, adware, backdoors, malicious BHOs, dialers, fraudtools, hijackers, keyloggers, malicious LSPs, rootkits, spyware, trojan horses and worms