Does a webpage with a black background save energy?

The answer in short: No, black color doesn't save energy in LCD monitors. It consumes a bit more! Black color save energy in CRT monitors (see history) and on OLED monitors (see at far future). Both of them almost doesn't exist in today days.

LCD panels make black pixels by blocking the colour filtered back-light from exiting the panel. It therefore uses a little more power to make black than to make white
See http://electronics.howstuffworks.com/lcd2.htm
LCD TV's sometimes have "dynamic contrast" LED back-lighting which should save power in black. This feature is sometimes found on high end IPS LCD monitors, though is useless for general computer use as the LED back-light resolution does not match the actual LCD resolution
OLED panels use power to make each individual coloured pixel, so black would save power. Who uses a couple of 24" OLED's yet?
See http://electronics.howstuffworks.com/oled2.htm
And more interestingly http://www.popsci.com/scitech/article/2009-09/mit-scientist-explains-oled-function-glowing-pickle

setup for win xp vpn server and a win7 vpn client

situation
	I want to use me computer as a personal FTP server.
problem
	setup for win xp vpn server and a win7 vpn client
difficulty level
	9/10 :>
compatibility
	Windows xp for VPN server, Win7 or any other windows version. Vpn client could be from any other system.
solution
	win xp, create a vpn server on win xp Control panel -> network connections -> create new connection -> Setup an advanced connection -> Accept incoming connections -> Connection devices: do not check anything, press next -> Allow private connections (this opens the firewall for internet connections) -> User permissions: select the user where will have vpn or create new Network software: TCP ip, in these parameters you should define the pool address that will take the connected vpn client. The first address of the pool will be used from the winxp server as vpn’s nic address and all the others will be given randomly to the connected vpn clients. You cannot easy the DHCP of server’s side.                                                                                   Setup is completed server’s side router, port forwarding From your router, you should forward the follow ports directly to win xp vpn server TCP & UTP 1720-1730 (range) TCP & UTP 120-150 TCP & UTP 500 win7, vpn client connection to win xp vpn server Control Panel -> Network and Sharing Center -> Setup a new connection to network -> Connect to a workplace -> Create new connection (do not choose any existed connection) -> Use my Internet connection (VPN) -> - Internet addess: give the ip or name of the win xp server [ [i] in case you do not have static ip use the NOIP free service ( http://www.no-ip.com/personal/ ) - Destination name: give a description of this connection - Do not use Smart card Voila! Enjoy your new VPN service… totally free.
attention
	- The two networks that are joined should have different address, for example: the one could be 192.168.0.xxx and the other cound me 192.168.124.xxx . - At the end of configuration you should make restart the Win xp vpn server, the Win7 vpn client and the Router, otherwize the vpn might not work with any kind of errors.

excel, how to get the Time value from a Timestamp value

excel, how to get the Time value from a Timestamp value? Or even from NOW() function? 

If we have the C2 cell with Timestame value, Time = C2-INT(C2)
In order to get only the time value from NOW() we have Time =NOW()-INT(NOW())

How to Disable Google Chrome Updates

Google Chrome’s automated update is a double-edged sword. On the plus side, it ensures users have the latest version of the browser: the Chrome 4 update was rolled out to everyone within a matter of weeks. However, many businesses take a more cautious approach. Few are willing to permit large-scale untested software updates, which could cause IT support issues or intranet application failures. IE6?s perseverance within the business world proves that many companies prefer the known risk of an unstable browser over the unknown risk of a shiny modern browser.Companies that have switched to Chrome are likely to define enterprise-wide policies for updates. Google provide an administrative template for Microsoft Windows Group Policy editor.Let’s assume you’re developing a web application for a company that uses Chrome 4 throughout its workplace. The last thing you need is Chrome to magically update to version 5 halfway through the development process. Fortunately, it’s possible to disable the automatic update on all operating systems.

Excel Keyboard Shortcuts

	NOTE: These key assignments are for standard US-English keyboards. The mappings may be slightly different on non-US-English keyboards.
	Key Alone Shift Ctrl Alt Shift Ctrl F1 Help What's This Help   Insert Chart Sheet   F2 Edit Mode Edit Comment   Save As   F3 Paste Name Formula Paste Function Define Name   Names From Labels F4 Repeat Action Find Again Close Window Quit Excel Find Previous F5 Goto Find Restore Window Size     F6 Next Pane Prev Pane Next Window Previous Window Prev Workbook F7 Spell Check   Move Window     F8 Extend Selection Add To Selection Resize Window Macro List   F9 Calculate All Calculate Worksheet Minimize Workbook     F10 Activate Menu Context Menu Maximize Window     F11 New Chart New Worksheet New Macro Sheet VB Editor   F12 Save As Save Open   Print A     Select All    Formula Arguments B     Bold     C     Copy     D     Fill Down Data Menu   E       Edit Menu   F     Find File Menu Font Name G     Goto     H     Replace Help Menu   I     Italics Insert Menu   J           K     Insert  Hyperlink     L           M           N     New Workbook     O     Open Workbook Format Menu Select Comments P     Print   Font Size Q           R     Fill Right     S     Save     T       Tools Menu   U     Underline     V     Paste     W     Close Workbook Window Menu   X     Cut     Y     Repeat Active     Z     Undo     ` (~)     Toggle Formula View   General Format 1 (!)     Cell Format   Number Format 2 (@)     Toggle Bold   Time Format 3 (#)     Toggle Italics   Date Format 4 ($)     Toggle Underline   Currency Format 5 (%)     Toggle Strikethru   Percent Format 6 (^)     Toggle Object Display   Exponent Format 7 (&)     Show/Hide Standard Toolbar   Apply Border 8 (*)     Outline   Select Region 9 (()     Hide Rows   Unhide Rows 0 ())     Hide Columns   Unhide Columns -     Delete Selection Control Menu No Border = (+) Formula   Calculate All Auto Sum Insert Cells [     Direct Precendents   All Precendents ]     Direct Dependents   All Dependents ; (semicolon)     Insert Date Select Visible Cells Insert Time ' (apostrophe)     Copy Formula From Above Style Copy Value Above : (colon)     Insert Time     /     Select Array   Select Array \     Select Differences   Select Unequal Cells Insert Insert Mode   Copy     Delete Clear   Delete To End Of Line     Home Begin Row   Start Of Worksheet     End End Row   End Of Worksheet     Page Up Page Up   Previous Worksheet Left 1 screen   Page Down Page Down   Next Worksheet Right 1 screen   Left Arrow Move Left Select Left Move Left Area     Right Arrow Move Right Select Right Move Right Area     Up Arrow Move Up Select Up Move Up Area     Down Arrow Move Down Select Down Move Down Area Drop down list   Space Bar Space Select Row Select Column Control Box Select All Tab Move Right Move Left Next Window Next Application Previous Window Enter   Move Up Fill Selection With Active Cell Insert Row   BackSpace   Collapse Selection To Active Cell Goto Active Cell
	You can download this as an Excel workbook here.