Portable softwares are such kind of applications which don’t need to install on a computer system. They can be run from anywhere(Hard disk, Pen drive, CD/DVD, etc) without installing. This is why they are called “Portable Application“. So they are easy to use and we can run them on a restricted computer where administrative privilege is needed to install any kind of software. And we can carry them with our external memory disks such as pen drives to use at outside home.

In operating systems windows has the maximum numbers of portable programs. There are many great resources to download portable softwares for windows. You can also make your own custom portable software with thinapp. Here I am going to give infos about some post popular and handy portable softwares for windows. If you are using any linux OS like ubuntu, you may want to get portable apps for Linux.

Most Important Free Windows portable apps worth carry on USB :

1. Mozilla Firefox Portable

Mozilla firefox is so far the best web browser. It has huge supports to get best out of internet. I suggest you to use portable firefox on public places where installed firefoxes can be vulnerable. It will increase your security and privacy . Don’t worry about your all settings, logins and plugins will be saved at your directory from where your firefox is running. There is also a great firefox with many security tools which is called “Firefox hacker Edition” which you can make portable using ThinApp. If you don’t like firefox, you may want to use Google chrome portable.
Download portable firefox from here.

2. VLC Media Player Portable

VLC media player is a simple open source media player with all things you need to play any media player. It can play almost all kinds of media files(MPEG-1, MPEG-2, MPEG-4, DivX, XviD, WMV, mp3, CDs, DVDs). It will be more helpful if you are unable to play a movie or song when outside home. You may want to use KMP Player portable if you don’t like VLC.
Download VLC portable from here.

3. 7-Zip Portable

If you don’t know what is 7-zip, it’s the most popular free alternative to winrar which can be used to open archive/zipped files like zip, jar, rar, 7z, tar etc. Some times we get archive files which we need to open to access files inside it. 7-Zip will help us to to use them. You can see more details about 7-zip archive manager.
Download 7-zip Portable from here.

4. Pidgin Messenger Portable

If you are outside home, you may need to chat with your friends at Yahoo, Facebook, Skype, MSN, GTalk or any other. skype plugin. Pidgin is the most popular all in one instant messaging To use Facebook and Skype with pidgin, you need to add facebook plugin and client which will give you ability to use almost all most use chatting services.
Download Pidgin from here.

5. ClamWin Portable Anti-virus

Portable antivirus is very uncommon. But a portable anit-virus you must need to scan a omputer for viruses, spywares and other malwares. Calmwin is such free antivirus which you can use to check whether the computer you are going to use is infected by malicious programs.
Download ClamWin portable antivirus from here.

6. Open Office Portable

Open office is the second leading open source and free office document manager after Microsoft Office. In some cases it can kick MS Office. You can do almost every thing including reading, creating or editing any type of office documents like doc, docx, ppt, pptx, xls etc.
Download open office portable from here.

7. Foxit PDF reader Portable

Foxit I think the most usable and user friendly free PDF reader. Besides reading you can also edit your PDF files/ebooks using it.
Download Foxit reader portable from here.

The download links I gave here are most from portableapps.com . Some of the applications you may need to extract to run. You can also make portable softwares using ThinApp and those apps no need to extract so you can run them directly.