This is a list of the free Windows apps I take everywhere with me.
Text editors, notepad replacements with syntax highlighting, auto-indenting & more:
Notepad2: http://www.flos-freeware.ch/notepad2.html (SDI)
Notepad++: http://notepad-plus.sourceforge.net/uk/site.htm (tabbed MDI)
WinZip replacement – extracts every compression format, including tar, bz, zip, rar, lzh, iso, arj, cab, 7z and more, and compresses to most formats as well:
7-Zip: http://www.7-zip.org/
FTP Client – Does most ordinary FTP tasks, handles secure ftp (SFTP), and has a server available in addition to the client:
FileZilla: http://filezilla-project.org/
PDF Viewer – lightweight and fast, just what you need and nothing you don’t:
Sumatra PDF: http://blog.kowalczyk.info/software/sumatrapdf/
PDF Maker – virtual printer driver that lets you create PDF files via the print menu from within any program:
PDFCreator: http://sourceforge.net/projects/pdfcreator/
Sandboxing / Virtualization Layer – lets you run programs in a sandbox having its own registry and filesystem, so no persistent changes can be made to your PC. Note: I'm not thrilled about Altiris being acquired by Symantec, but so far SVS hasn't seemed to suffer from Symantecitis...
Sandboxie http://www.sandboxie.com/
Altiris SVS http://www.altiris.com/Products/SoftwareVirtualizationSolution.aspx
Hardware Emulator / Virtual Machine -- allows you to run a virtual machine "computer" as an application, like when you want to run Windows on top of Linux or vice versa, or any time you need a specific environment that's isolated from your main PC.
http://www.vmware.com/download/server/
ISO Manager – create .iso file images of CDs or DVDs, make a CD or DVD from an .iso image, make an .iso image of a set of folders/files which can later be burned to a disk, all from the context-menus in Windows Explorer:
ISO Recorder http://isorecorder.alexfeinman.com/isorecorder.htm
Virtual CD-ROM/DVD-ROM Emulator – mount an .iso file on your hard drive or USB drive or network, and Windows will treat it like another CD/DVD drive:
Daemon Tools: http://www.daemon-tools.cc/dtcc/download.php
Full-featured CD/DVD Burner & image recorder:
CDBurnerXP: http://cdburnerxp.se
Video Player – lightweight player can play DVDs, .iso images of DVDs, streaming content, just about any video file you throw at it, and even has a built in http server you can use to stream video with:
VideoLan: http://www.videolan.org/vlc/
Audio Player – lightweight player that handles all the audio formats that WMP doesn’t, including open-source formats like .ogg and .flac. Very plain, small footprint, but can be customized to look how you want if you get the “ColumnsUI” plug-in. Also rips CDs, optionally using the LAME MP3 encoder.
Foobar2000: http://www.foobar2000.org/
Image Editor: Aims to become a complete replacement for PhotoShop; right now it’s not quite there, but still the best free image editing software I’ve seen:
PaintDotNET: http://www.getpaint.net/index.html
Video Converter – converts almost any audio or video format to any other; lets you crop videos, adjust colors and cut off portions of the beginning or end while transcoding:
MediaCoder: http://mediacoder.sourceforge.net/
Web Browser – no list of free software would be complete without Firefox, the lightweight, faster, more customizable and more-secure alternative to Internet Explorer:
Mozilla Firefox: http://www.mozilla.com/en-US/firefox/
As of this writing, the Opera Browser is at its 9.5 beta release, and it's quite nice; check out the unique "Speed Dial" homepage feature, and if you can never have enough screen real-estate for your browser, hit F11 to check out its corner-to-corner fullscreen mode:
Opera Browser: http://www.opera.com/products/desktop/next/
Office Suite – complete replacement for Microsoft Office as free, open-source software that runs on any platform (Windows, Linux, Mac, etc.):
OpenOffice http://www.openoffice.org/
Antivirus – even the free version of their antivirus is quite capable, and it uses far less system resources than Symantec, McAffee or TrendMicro.
AVG Free http://free.grisoft.com/
Peer-to-Peer client, Gnutella network (like LimeWire):
FrostWire is the free, open-source counterpart to LimeWire pro: http://www.frostwire.com
If you enjoy FrostWire, you can get new features a bit sooner by purchasing LimeWire Pro; they's good peeps over dar, they've done quite a bit of good work on this P2P client.
BitTorrent Clients:
Azureus: http://azureus.sourceforge.net (full featured)
uTorrent: http://www.utorrent.com (aka Micro-torrent, literally “µTorrent”)
BitTorrent: http://www.bittorrent.com (slim)
Privacy, Anonymity and Security-enhanced web browser – encrypts all your traffic (including the domains and IP addresses you request), and routes it through a network of onion-routers, so no middleman – including your ISP – can sniff or log your traffic:
XeroBank http://xerobank.com/xB_browser.html
Portable Applications – all the basics like Instant Messaging, Email, Office, Antivirus and Web Browsing, but everything’s been modified to run from a USB stick withoutneeding any installation:
PortableApps http://portableapps.com/
File Wiper – Securely erase sensitive data
Eraser http://www.heidi.ie/eraser/
Text, File and Email Encryption – cross-platform PGP-compatible tool to allow secure data exchange:
GPG: http://www.gnupg.org/
The FireGPG extension for Firefox lets you encrypt, decrypt and sign data in web pages, and as a bonus, integrates right into GMail. http://firegpg.tuxfamily.org/
Whole Drive Encryption – allows you to mount a file, a partition or a whole disk as a separate drive in Windows, and encrypts/decrypts data on-the-fly while the drive is mounted. Data is unreadable when not mounted with the correct password.
TrueCrypt http://www.truecrypt.org/