Working with Windows

A window is a rectangular frame in which a program or folder is displayed.

1. Title bar — the strip across the top showing the name of the document or folder. Dragging it moves the window; double-clicking it maximises or restores.

2. Minimise button — reduces the window to a taskbar button. The program keeps running and unsaved work is retained.

3. Maximise / Restore button — expands the window to fill the screen; when already maximised the same button restores the previous size.

4. Close button — closes the window, and ends the program if it was the last window. Prompts to save unsaved work.

5. Menu bar / ribbon — the commands available in the program, grouped into menus or tabs.

6. Toolbar — buttons for frequently used commands.

7. Work area (client area) — where the document or folder contents appear.

8. Scroll bars — vertical and horizontal, appearing only when the contents are larger than the window, and dragged to see the rest.

9. Status bar — information at the foot: page number, word count, number of items selected.

10. Borders and corners — dragged to resize the window.

The important distinction: minimise hides, close terminates. A minimised program still occupies memory.

A file extension is the group of letters following the final dot in a file name — the .docx in notes.docx. It identifies the type of the file, and Windows uses it to decide which program should open the file and which icon to display.

Others: .txt plain text, .mp3 audio, .mp4 video, .zip compressed archive, .html web page, .c C source code.

A caution. Renaming photo.jpg to photo.docx does not convert it. The extension is only a label; the contents are unchanged, so Word will open it and report a damaged file. Conversion requires a program that actually rewrites the contents.

A security note. Because the extension decides what Windows does with a file, attackers disguise programs as documents — invoice.pdf.exe looks like a PDF when extensions are hidden but is an executable. This is why displaying file extensions should be left switched on.

Copy against move.

Note also that dragging a file with the mouse within the same drive moves it, but dragging it to a different drive copies it — which is why cut-and-paste is the safer habit when the intention matters.

Deleting to the Recycle Bin against permanent deletion.

A subtlety worth stating. "Permanent" deletion removes the file's directory entry and marks its blocks as free, but does not immediately overwrite the data. Until those blocks are reused, specialist recovery software can often retrieve the file. Genuinely destroying data requires overwriting it, or encrypting the drive and discarding the key — which matters when disposing of an old computer.

When the Bin is not used at all: Shift+Delete; deletion from a pen drive, memory card or network drive; or a file too large for the space allotted to the Bin.

A shortcut is a small file that acts as a pointer to another item — a file, folder, program or device stored elsewhere. It is recognised by a small curved arrow on its icon. Double-clicking a shortcut opens the item it points to, exactly as if the item itself had been opened.

Differences from the actual file.

What happens on deletion.

• Delete the shortcut — only the pointer is removed. The actual file is untouched and still in its folder. Nothing is lost.
• Delete the actual file — the data is gone. The shortcut survives but is now broken: double-clicking it produces an error saying the item cannot be found. Windows may offer to delete the dead shortcut.
• Move or rename the actual file — Windows can often repair the shortcut automatically within the same drive, but a move to a different drive or a deletion usually breaks it.

Why shortcuts exist. A program installed once in C:\Program Files can be reached from the desktop, the Start menu and the taskbar simultaneously, without three copies of the program existing. Space is saved and, more importantly, there is only one copy to update.

Common exam trap. Deleting a desktop shortcut does not uninstall a program. Uninstalling is done through Settings → Apps or Control Panel → Programs and Features.

The clipboard is a temporary area of main memory, managed by the operating system, that holds data which has been cut or copied so that it can be pasted elsewhere.

Its role in the three operations.

• Copy (Ctrl+C) — places a duplicate of the selection on the clipboard. The original is unchanged.
• Cut (Ctrl+X) — places the selection on the clipboard and removes it from its source.
• Paste (Ctrl+V) — inserts the clipboard contents at the current position. The clipboard is not emptied, so the same item can be pasted repeatedly, in as many places as needed.

Why it matters that the OS owns it. Because the clipboard belongs to the operating system rather than to any one program, it works between programs: a table copied in Excel can be pasted into Word, and text copied from a browser into Notepad. This is one of the main practical benefits of a common operating system beneath all applications.

Limitations.

1. It holds one item at a time. Each new cut or copy replaces the previous contents, which are then gone. Copying a second item before pasting the first loses the first — the commonest cause of accidental data loss in office work. (Windows offers Clipboard History, Win+V, to mitigate this, and Office keeps a multi-item clipboard of its own.)

2. It is volatile. The clipboard lives in RAM, so its contents are lost when the computer is shut down or restarted, and often when the source program is closed for large items. Data must never be "stored" on the clipboard even briefly across a restart.

Further points: pasting may lose formatting depending on the destination, which is why Paste Special offers choices such as keeping the source formatting, matching the destination, or pasting unformatted text; and copying very large items consumes real memory.