Scandisk also known as CheckDisk in previous version of Windows Operating System is a tool for checking the disk for any errors. One could wonder what these errors are and how do they come on my Hard Drive? The answer to this is simple and if you understand the basic read/write operation on a hard drive you can understand this easily. Have you ever noticed what happens when you try to move or copy a file which is in use by any application? We get a message stating the operation could not be completed because file is in use. This happens because whenever we open a file its handles or headers get locked and it remains locked until the file is closed by the application using it. Now what if a file was open and your computer shuts down abruptly. In this case the file remains in locked state and might get corrupted or unusable the next time when you try to open it. Check disk performs several scans on the hard drive to find out such locked files and fixes the problem by restoring the data (if any) and unlocking them for future use.
In earlier Operating Systems like Windows XP or Windows 2000 you would have noticed the black and white screen which starts automatically whenever you boot the computer and it scans for any disk errors. This happens because your computer would have not shut down properly during the last session. The same tool has been continued in Windows Vista but has some more advanced features and complex ways of checking the hard drive. Let’s see how to invoke scandisk in Windows Vista.
To start Scandisk in Windows Vista, click on the Start button and then open Computer. Once you have the Computer window open you will find all the drives listed there. Right Click on the drive you want to scan and select Properties. Once the properties window is up click on the Tools tab. In the Tools tab you will find a box titles Error Checking and there would be a button named Check Now. Click on Check Now to start the Scandisk to scan your selected drive. Basis your account type you might be prompted for entering the Administrators password and only then the Scandisk would continue.
Unlike Scandisk of previous operating Systems the Windows Vista’s Scandisk works in 5 different stages and takes considerably long time to complete. In the first stage Scandisk searches and processes Tests files and files that are large in size. It also looks for any bad files or damaged files because of improper shutdown. In second stage it checks the files systems index and file indexes to ensure the database in shape. It tries to index the un-indexed files or the lost files. It further checks the security descriptors (NTFS file system) for any problems. Security descriptors are the values stored in each file regarding its security and accessibility. In the fourth step the actual data of the file is checked and fixed in case of any errors. Finally the last stage of Windows Vista Scandisk start and this is the stage which takes the most of the time. If we compare the time then this stage takes almost 70% of entire time consumed by Scandisk. In this stage Scandisk finds and verifies the free space on the hard drive. Larger the hard drive more time it needs to be checked.
Though the Scandisk tool in Windows Vista is very comprehensive but Microsoft should do something to make it a little less time consuming.