1. TESTING ANTI-VIRUS EFFECTIVENESS:
You can test your anti virus program for its effectiveness via this Notepad trick. To check your anti-virus:
Open Notepad. Copy the code give below in the notepad file:
X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H*
Save it with an .exe extension, like testvirus.exe.
Soon as you save this file, your anti virus program will detect the file (test virus) immediately and will attempt to delete it. If this happens then your Antivirus is working properly. If not, then its time for you to change your PC anti virus program.
This EICAR test file is a 16-bit application & can't be run on 64-bit versions of Windows.
My PC Anti-virus given above warning soon after creating that test file.
2. FLUSH DNS CACHE:
Most operating systems and DNS clients automatically cache IP Addresses & other DNS results, this is done in order to speed up subsequent requests to the same hostname. Sometimes bad results will be cached & need to be cleared from the cache in order for you to communicate with the host correctly. All major operating systems allow you to force this process. Copy the code given below in notepad:
@echo off
echo ipconfig /flushdns
ipconfig /flushdns
echo ipconfig /release
ipconfig /release
echo ipconfig /renew
ipconfig /renew
And save it as flushdns.bat.
Now click on that file whenever you need to clear DNS cache.
You can do clear DNS cache via Command Prompt too. Just Click the Start button> Accessories> Command Prompt> Right click on it & open it as Administrator.
Type ipconfig /flushdns in the command prompt & hit enter, It will clear DNS cache. You can flush DNS cache on computers running... Windows 2000, Windows XP, Windows Server 2003, Windows Vista and Windows 7 operating systems.
3. CREATING PERSONAL DIARY OR A LOG-BOOK:
We can use Notepad as a simple digital diary or a personal Log-Book. Follow the below mentioned steps to make Diary or Log-Book for yourself:
Open Notepad.., Type .LOG (in capital letters) and press Enter. Save it with any name and close it. That's it... your Diary is created.
From now on... Whenever you open that Notepad file you will see the current date and time being inserted automatically after the .LOG line. This will happen automatically every time you open that notepad file. So there will be no need to manually enter date and time whenever you write something in that file.
Screen shot of the Notepad Diary which is created using above trick.
Links will not work for long so hurry up.
In short... Every data which is in your PC's clipboard is unsafe and can be accessed-stolen by website or hacker if your PC is connected to internet. 
Please don't. Because nothing is safe on PC from expert hackers. 
So never keep any sensitive information in your computer if your computer is connected to internet.
