Restoring mozilla's bookmarks

Firefox 3 no longer uses bookmarks.html to store the bookmarks. It stores the bookmarks and the browser history in places.sqlite and no longer creates a HTML backup by default instead there are also JSON backups in the bookmarkbackups folder within the Firefox profile folder.
Check for backups in following path : 
C:\Documents and Settings\<User Name>\Application Data\Mozilla\Firefox\Profiles\<some  folder>\bookmarkbackups


See Lost_Bookmarks (MozillaZine KB)
You can export the bookmarks in Firefox to a HTML file: Bookmarks > Organize Bookmarks > Import & Backup > Export HTML
You can also create a JSON backup: Bookmarks > Organize Bookmarks > Import & Backup > Backup

If migrating to new account , then just copy the latest JSON file to new account's bookmarkbackup folder and restore it in mozilla.
You should restore a JSON backup: Bookmarks > Organize Bookmarks > Import & Backup > Restore-> Choose file
 Restoring a JSON backup will replace all existing bookmarks. You can merge bookmarks if you import a HTML backup.

A HTML backup doesn't support tags and annotations, so if you want to preserve those then you need to use a JSON backup.

How to remove autorun virus from Hard disk or How to open HDD by double click

Some time you are not able to open your hard disk drives(HDD) by double clicking, so to enable that please follow following procedures:
> open command prompt
> type and enter "cd\", this will take you to the root of C: Drive
> type "attrib -h -r -s autorun.inf" and enter
> now type and enter "del autorun.inf" to delete autrun.inf file
> Similarly follow same steps for all the drives and then restart your computer
> Same steps can also be followed for pendrives or removable media.

> Now just enjoy the freedom of double clicking.

Getting Information about file

File Checking
Existence:

if( -e $file) { print "File exists \n";}
else { print "File doesn't exist\n"; }

File exists with size 0(zero) : -z
File exists with size non-zero : -s

Readable/writable/Executable

File Readable : -rFile Writable : -w
File Executable : -x

Text/Binary

Text : -T
Binary : -B

Enabling Task Managaer disabled by Virus

Method 1:
> Open Run window and type gpedit.msc and click ENTER.
> Now Goto location: User Configurations/Administrative Templates/System/Ctrl+Alt+Del Options

> Double click on Remove Task Manager on right side Pane. And select the value as "Not Configured" as follow.

Method 2:
> start "RUN" Window and type regedit and Enter
> GoTo this registry index: HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies\ System
> In the right pane, find and delete the value named as DisableTaskMgr 
> Close  Registry Editor