This is questions which everybody has... but cant guess it...... well if you have windows XP, i don't think u need to do anything. Well first i would like to add that if the file is hidden it will not show up search results. For *.doc you can also make it password protected.
check this link
http://wordprocessing.about.com/cs/quicktips/qt/Passprotect.htm
Below i have given four procedures according to your need you can chose.
first of all you to follow this small procedure....
Covert your Hard Disk partitions from FAT32 to NTFS.
What is NTFS .. you will get your answer here
http://en.wikipedia.org/wiki/NTFS
Well in short NTFS is basically for system security.
Well you can convert it without formatting the disk.
Here the procedure is given how to convert. Basically C: has to be converted to NTFS to see the effects.
http://support.microsoft.com/kb/307881
The disadvantage is you can't run two operating system like windows xp and windows 98 or Linux. Well I don't want you to get confuse... now if your have made your main drive C: drive NTFS. restart the system. Also make all other drives NTFS then go to accounts in control panel. Create your account with password..... after you make that it will ask you to make your documents private. So now all your documents in my documents cant be accessed by anybody. But for that you should be administrator.
Second Procedure is encryption.
For more details check out this link below:
http://www.truecrypt.org/
read the details. With this you can hide whole your drive.
For this again you should be the administrator.
Third procedure is Folder lock which is mentioned above
here is the link
http://www.newsoftwares.net/folderlock/
But to crack it all you need is reinstall it on the same location. Gone all your hidden files. Anybody can see it whoever reinstalls it.
Fourth option can be possible in any folder but not on desktop. First change its icon with some white color plain icon matching the background. rename it with pressing ALT+255. It will give it a blank name. Only problem is you have to remember its location where the folder is placed inside the main folder. Cause where will you click otherwise.
Last option I got from somewhere is in DOS. Below is the code. Copy the following program:
****************** copy from here
cls
@ECHO OFF
title Folder Locker
if EXIST "Control Panel.{21EC2020-3AEA-1069-A2DD-08002B30309D}" goto UNLOCK
if NOT EXIST Locker goto MDLOCKER
:CONFIRM
echo Are you sure u want to Lock the folder(Y/N)
set/p "cho=>"
if %cho%==Y goto LOCK
if %cho%==y goto LOCK
if %cho%==n goto END
if %cho%==N goto END
echo Invalid choice.
goto CONFIRM
:LOCK
ren Locker "Control Panel.{21EC2020-3AEA-1069-A2DD-08002B30309D}"
attrib +h +s "Control Panel.{21EC2020-3AEA-1069-A2DD-08002B30309D}"
echo Folder locked
goto End
:UNLOCK
echo Enter password to Unlock folder
set/p "pass=>"
if NOT %pass%==type your password here goto FAIL
attrib -h -s "Control Panel.{21EC2020-3AEA-1069-A2DD-08002B30309D}"
ren "Control Panel.{21EC2020-3AEA-1069-A2DD-08002B30309D}" Locker
echo Folder Unlocked successfully
goto End
:FAIL
echo Invalid password
goto end
:MDLOCKER
md Locker
echo Locker created successfully
goto End
:End
*********************** copy till here
* Now paste it in notepad.
* Save it as batch file(with extension .bat).Any name will do.
* Now you see a batch file. Double click it to create a folder locker.
* A new folder named Locker would be formed at the same location.
* Now brings all the files you want to hide in the locker folder.
* Now double click the batch file to lock the folder namely Locker.
* If you want to unlock your files,double click the batch file again and you would be prompted for password.Enter the password and enjoy