Function Keys

Shortcut Key	Function(s)
F1	Start Help (supported in most applications).
F2	Rename selected icon or file in Windows Explorer or on the Desktop.
F3	Open Search (in Windows Explorer or on the Desktop only).
F4	Open a drop-down list (supported in many dialog boxes). For example, press F4 in a File Open dialog to drop down the Look In list.
F5	Refresh the view in Windows Explorer, on the Desktop, in the Registry Editor, and some other applications.
F6	Move focus between panes in Windows Explorer.
F10	Send focus to the current application’s menu.

Miscellaneous Keys

Shortcut Key	Function(s)
Arrow Keys	Basic navigation - move through menus, reposition the text cursor (insertion point), change the file selection, and so on.
Backspace	Move up one level in the folder hierarchy (Windows Explorer only).
Delete	Delete selected item(s) or selected text.
Down Arrow	Open a drop-down listbox.
End	Go to end of line when editing text, or to the end of file list.
Enter	Activate highlighted choice in menu or dialog box, or insert a carriage return when editing text.
Esc	Close dialog box, message window, or menu without activating any choice (usually the same as clicking Cancel).
Home	Go to beginning of line (when editing text), or to the beginning of file list.
Page Down	Scroll down one screen.
Page Up	Scroll up one screen.
PrintScreen	Copy entire screen as a bitmap to the Clipboard.
Space Bar	Toggle a checkbox that is selected in a dialog box, activate the command button with the focus, or toggle the selection of files when selecting multiple files with Ctrl.
Tab	Move focus to next control in a dialog box or window (hold Shift to go backward).

Alt Key Combinations

Shortcut Key	Function(s)
Alt	Send focus to the menu (same as F10). Also turns on the menu in applications where it is no longer used by default, such as Windows Explorer and Internet Explorer.
Alt-x	Activate menu or dialog control, where letter x is underlined (if the underlines are not visible, pressing Alt will display them).
Alt-double-click (on icon)	Display Properties sheet.
Alt-Enter	Display Properties sheet for selected icon in Windows Explorer or on the Desktop. Also switches command prompt between windowed and full-screen display.
Alt-Esc	Drop active window to bottom of pile, which, in effect, activates next open window.
Alt-F4	Close current window; if Taskbar or Desktop has the focus, exit Windows.
Alt-hyphen	Open the current document’s system menu in a multiple document interface (MDI) application.
Alt-numbers	When used with the numbers on the numeric keypad only, inserts special characters corresponding to their ASCII codes into many applications. For example, press the Alt key and type 0169 for the copyright symbol. Check characters map for full list of codes.
Alt-PrintScreen	Copy active window as a bitmap to the Clipboard.
Alt-Shift-Tab	Same as Alt-Tab, but in the opposite direction.
Alt-Space Bar	Open the current window’s system menu.
Alt-Tab	Switch to the next running applicationhold Alt while pressing Tab to cycle through running applications.
Alt-M	When the Taskbar has the focus, minimize all windows and move focus to the Desktop.
Alt-S	When the Taskbar has the focus, open the Start menu.

Ctrl Key Combinations

Shortcut Key	Function(s)
Ctrl-A	Select all; in Windows Explorer, selects all files in the current folder. In word processors, selects all text in the current document.
Ctrl-Alt-x	User-defined accelerator for a shortcut, in which x is any key.
Ctrl-Alt-Delete	Show the logon dialog when no user is currently logged on; otherwise, switch to the Windows Security dialog, which provides access to Task Manager and Log Off, as well as switching to another user, allowing you to change your password or lock the computer. Use Ctrl-Alt-Delete to access the Task Manager when Explorer crashes or your computer becomes unresponsive.
Ctrl-arrow key	Scroll without moving selection.
Ctrl-click	Use to select multiple, noncontiguous items in a list or in Windows Explorer.
Ctrl-drag	Copy a file.
Ctrl-End	Move to the end of a document (in many applications).
Ctrl-Esc	Open the Start menu; press Esc and then Tab to move focus to the Taskbar, or press Tab again to move focus to the Taskbar, and then cycle through the toolbars on the Taskbar every time you press Tab.
Ctrl-F4	Close a document window in an MDI application.
Ctrl-F6	Switch between multiple documents in an MDI application. Similar to Ctrl-Tab; hold Shift to go in reverse.
Ctrl-Home	Move to the beginning of a document (in many applications).
Ctrl-Space Bar	Select or deselect multiple, noncontiguous items in a listbox or in Windows Explorer.
Ctrl-Tab	Switch among tabs in a tabbed dialog or Internet Explorer; hold Shift to go in reverse.
Ctrl-C	Copy the selected item or selected text to the Clipboard. Also interrupts some command prompt applications.
Ctrl-F	Open Search (in Windows Explorer or on the Desktop only).
Ctrl-V	Paste the contents of the Clipboard.
Ctrl-X	Cut the selected item or selected text to the Clipboard.
Ctrl-Z	Undo; for example, erases text just entered, and repeals the last file operation in Windows Explorer.

Shift Key Combinations

Shortcut Key	Function(s)
Shift	While inserting a CD, hold to disable AutoPlay.
Shift-arrow keys	Select text or select multiple items in a listbox or in Windows Explorer.
Shift-click	Select all items between currently selected item and item on which you’re clicking; also works when selecting text.
Shift-click Close button	Close current folder and all parent folders (Windows Explorer in single-folder view only).
Shift-Alt-Tab	Same as Alt-Tab, but in reverse.
Shift-Ctrl-Tab	Same as Ctrl-Tab, but in reverse.
Shift-Ctrl-Esc	Open the Task Manager.
Shift-Delete	Delete a file without putting it in the Recycle Bin.
Shift-double-click	Open folder in two-pane Explorer view.
Shift-Tab	Same as Tab, but in reverse.

Windows Logo Key (WIN) Combinations

Shortcut Key	Function(s)
WIN	Open the Start menu.
WIN-Tab	If the Aero interface is active, this activates Windows Flip 3D.
WIN-Pause/Break	Display System Control Panel applet.
WIN-Space bar	Display the Sidebar.
WIN-D	Minimize all windows and move focus to Desktop.
WIN-E	Start Windows Explorer.
WIN-F	Launch Search.
Ctrl-WIN-F	Search for a computer on your network (requires Active Directory).
WIN-L	Lock computer, requiring password to regain access.
WIN-M	Minimize current window.
Shift-WIN-M	Undo minimize current window.
WIN-R	Display Run dialog.
WIN-U	Open the Ease of Access Center.

If you have tried to sniff the packet traffic of an ongoing MSN chat (with a Wireshark client), you will notice that the protocol used between the sender and the recipient is msnp (1863).

Enter "msnms" in the Wireshark display Filter text box to narrow down the display packets if you did not use any capture filter during the Wireshark capture.

In the screen capture below, ip address 192.168.1.106 is my desktop.



To figure out the "owner" of ip address 64.4.37.20, I use the Whois feature from the website www.samspade.org. If you would like to resolve the ip_address-to-dns_name, use nslookup.



From the information gathered from this snoop capture, we find out that my desktop establishes a connection to the MSN Hotmail server instead of a direct connection to the ip address of the remote MSN friend whom I was having a text conversation with.

As I was working on a pile of paperwork, I realized that I need to convert a pdf document into a MS-word document format for some extensive editing. Previously, I was able to retrieve the documents in pdf and MS-word format. However, recently the document creator decided to stick with publishing the documents in pdf and sdif format. (What in the world is sdif format anyway? Who uses it?)

At about the same time as I was pulling my hair over the issue above, my colleague had a requirement to convert a pdf document to Excel format and he asked me for some help. Great!

I googled around and found a pretty cool software which could handle the document conversions from PDF to Excel/Word and more! Able2Extract 5.0

It is relatively simple to get the hang of using the software, and you can select portions of the document for conversion into the desired format.

If you are not convinced, download the 7-Day Trial copy and try it out for yourself. And in case you are wondering about the difference between the Able2Extract 5.0 and the Able2Extract 5.0 Professional, you can check out the product comparison here.

Hope you find this recommendation beneficial!

Protocol Data Unit (PDU)
- comprises of the Layer's Header + Upper Layer's Data
- The figure below shows an example of a PDU:











Service Data Unit (SDU)
- a subset of PDU
- comprises of the Upper Layer's PDU
- In the OSI Layer encapsulation, where the OSI Layer goes from N to N-1, the Upper Layer's PDU becomes the SDU in Layer N-1. The figure below shows the example:

To translate an IP address from a string of decimals (in little endian* order) into a real IP address, follow this procedure:

Using the decimal number 26999818 as an example.

1) Convert the number to hex

    26999818 (in dec) = 19BFC0A (in hex)

2) If the hex number is 7 digits long, add a leading 0. If the hex number is 8 digits, skip to step 3.

    => 019BFC0A (in hex)

3) Split this value into 4 bytes

     01 9B FC 0A

4) Reverse the order of the bytes, as this value is little endian*

    0A FC 9B 01

5) Convert each byte (in hex) back to decimal

    10 252 155 1

This is the real IP address in dot-decimal notation: 10.252.155.1


*The least significant byte (LSB) value, 0x01, is stored in memory at the lowest address. And the most significant byte (MSB) value, 0x0A, is stored in memory at the highest address.

Note: For a better understanding on "Endian", check out the explanation here.