Many a people still don’t understand what the correct aspect ratio of an image or a video is. It is the correct ratio between its width and height which will make the image look normal to the eyes and not like a print on a stretched balloon.

Wrong aspect ratio

Correct aspect ratio

How do you correct if a video has wrong aspect ratio.

Video :

If the aspect ratio of a video is not correct then play it in VLC media player. Goto full screen mode and press “A” on the keyboard. This will change the aspect ratio. Repeatedly press the key until the aspect ratio is OK. Alternatively you can right click the screen and goto Video>>Aspect Ratio and select an aspect ratio from the list.

o adjust the aspect ratio of an image could be done using more than one tool. I will explain this in a later post.

There was a small introduction on how files are recovered from magnetic media in the last post. In that post I had said about using repeated overwrites to render a file unrecoverable. Sdelete is a command line utility that can wipe off a file and its traces completely from your hard disk without leaving a chance for recovery. If you have some data that you don”t want others to know about, you can “securely delete” it using sdelete.

sdelete is a tool from sysinternals to erase data from Disk drives completely. It can delete data from USB drives, floppy drives, or hard disk drives. sdelete can also cleanup the freespace avilable on any drive with zeros and delete directories recursively.

You need to download the zip file from sysinternals site, extract it to C:\WINDOWS or C:\WINDOWS\system32 folder (or you can add the folder you are extracting to the PATH variable in Windows environment). so that it can be directly accessed from command prompt.

Usage :

sdelete [-p passes] [-s] [-q] <file or directory>
sdelete [-p passes] [-z|-c] [drive letter]

sdelete is free, light and installation free. You can control the number of passes (overwritings) that has to be done and moreover previously deleted file data can also be cleaned using the free space cleaning facility.

Download sdelete(free) (47Kb) , Visit sdelete webpage on Sysinternals

In the previous post we discussed why deleted files are recoverable from a drive? So lets look at how we can actually remove the file contents from the hard disk which may be needed if you have got confidential data. In any of the present filesystems, the OS doesn’t actually wipe the data contained in a file when it is deleted. But rather the metadata of the file is deleted. In order for a file to be unrecoverable it should be overwritten with some random data. To save processing and other system resources, the OS will simply delete it from corresponding indexes.

Peter Gutmann of Auckland University presented a paper that explained recovering data that has been overwritten by other data on a Magnetic storage media. Theoretically this could mean anybody can recover data aging back to any time from a drive, but practically this is very hard (forget about the any date part). Even recovering data with just a single pass overwrite is difficult.

The number of passes used during an overwrite of a file to render it unrecoverable doesn’t need to be given much importance for normal uses. A 4 pass would be sufficient if you have the time. If your disk fills up easily you may need to use just a single pass and save time.Here a pass means writing the file using pseudo random data in order to render it unusable.

If you have anything confidential on your harddisk, consider deleting it using a file shredder like Window Washer, sdelete, or using a degausser.

This is a small list of folders and files which were displayed by the method mentioned on the previous post in this series.

Hidden folders and files in C drive of Windows

Recycler : Recycler is aanother form of Recycle Bin. The Recycler folder contains a Recycle Bin for each user that logs on to the computer, sorted by their security identifier (SID).

System Volume Information : This contains the log files and backups of important System Files that are used for System Restore in Windows. (System Restore allows you to roll back all the settings and System Files to a previous time)

MSOCache : MSOCache is the folder that contains cached Office installation files. The folder is safe to delete.

NTLDR : This is the Windows NT boot loader. This is replaced by winload and Windows Boot Manager in Windows Vista

NTDETECT.COM : This file is used by Windows NT during startup to detect basic hardware required to boot the OS. This is used for Systems having BIOS.

Autoexec.bat : is most often used to set environment variables such as keyboard, soundcard, printer, and temporary file locations. It is also used to initiate low level system utilities.
These are the main folders and files in XP.

pagefile.sys : This is the actual pagefile, as the name indicates, of Windows. This file is used as virtual memory on your system.

hiberfil.sys : As the name indicates this is the file used for Hibernation. While hibernating the system stores all the content of the RAM to this file and shuts down. The next time you start your system the RAM contents are restored from this file.

On the last article we have discussed about seeing all the files that are part of Windows. Now lets see whether we can directly access these folders. As it turns out Windows by default will not grant you permission to the folder System Volume Information.

Thats because the folder contains important System Restore Point informations. So what do you do when you can’t touch your own property. well it is there that the Windows file sharing comes into play. It may sound a little weird at first but it is true. Lets see how.

Step 1 : Go to Tools>>Folder Options and select View tab.

Here scroll down to the bottom, you can see a check box named Use Simple File Sharing (Recommended), UNCHECK the box, click APPLY and OK. Now you are done with the settings part. So just take the Properties (ALT+ENTER) or RIGHT CLICK>>PROPERTIES) of System volume Information you can see a new tab named Security here. You can see that there will be a user named SYSTEM there and it has full permission (refer picture).

You need to add your User account as a user here and give full permission to your self in order to gain access. Click Add button and type in your user name and click Check Names your user name will be filled along with the computer name automatically.

Click OK. now just click on user name of yours and check Full control. Click Apply, OK and you are done.

You can get access to files that return an “Access Denied” error by using this method. are some Files and Folders which need some more work to open I’ll discuss it in next post. Till then try this and figure out what all were hidden from you.

This is the first among a series of posts on administering Windows . It starts with how to see the files and folders that were hidden by Windows for some reason. The series is actually inspired from the one done by Samanathon on Starting your Day with a fresh Computer. He did a good job and I am a regular visitor of Saman’s Blog.

A Super Hidden or a Protected Syetem File is a file that is normally not shown in the Windows Explorer even if you have enabled Show Hidden files (Tools>>Folder Options>>View>>Show Hidden Files and Folders) in Windows Explorer). This is because if some of these files are deleted or changed Windows may encounter a fatal error. Some of such folders are :

• C:\Windows\system32\dllcache
• System Volume Information – this is in all the drives
• Recycler – which is also in all the drives

So the first step involved is to make Windows show all the Super Hidden files. This can be done in two ways. One is directly through Windows Explorer Tools>>Folder Options and the other is through . So the former being easier and straight forward I’ll discuss it first.

1 . Through Windows Explorer

In Windows Explorer from Tools (Alt+T) menu take “View” tab in “Folder Options”.Make sure that you have selected Show Hidden Files and Folders and that you have unchecked Hide Protected operating system files options. Click Apply and then OK. This will enable you to see system files that had previously been hidden from your view.

2 . Through Registry Editing

This is a little more complex.(It is recommended that you read the following posts before you go into the registry. Try this if you know Registry editing. Make a backup of the registry before you proceed.( The Introduction to Windows Registry , Know how to backup your registry )

Follow these steps..

1 . Run ( WIN+R ) regedit and open registry editor.

Go to the Key HKEY_CURRENT_USER\Software\Microsoft\Windows\
CurrentVersion\Explorer\Advanced.

2 . In there you will see a Registry DWORD named ShowSuperHidden Make the value 1 instead of 0.

3 . Now all you need to do is to restart Windows Explorer. to do so you can goto Start>>Shut Down and Click Cancel while holding down SHIFT+CTRL+ALT. Now press ALT+CTRL+DEL this will bring Task Manager. Take File>>New Task and type explorer and press Enter.

Now if you go to any drive you can see the previously Hidden files there. Note that you will still need to enable Show Hidden files option in Folder Option.