SE-Explorer is a free and powerful file manager for Windows and a complete portable replacement of standard Windows Explorer.
It has tabbed interface which made it possible to manipulate more than one directory or file view at the time, dual-panel file manager with two file windows side by side; new powerful search feature that allows to search media files, text in files, recently changed documents, files by tags, resources; new embedded size scanner that allows you to view disks summary, folders size, file types, size and extentions info and top largest files, powerfull file compare tool.

Moreover SE-Explorer offers lots of build-in viewers:

Media player for audio, video and flash files: MP3, AVI, DIVX, MPEG, WMV, SWF, MOV, DV, DVR-MS, etc. FLV files are supported!
Picture viewer for PSD, PNG, JPEG, TIFF, PCX, TGA, etc.
DLL Inspector component. It has embedded resource view, object browser and dependencies walker for EXE, DLL and OCX files.
Archive explorer for ZIP, RAR, ISO, MSI, CAB, etc.
Resource view for executable files and icon libraries.
DOC, WRI, PDF, DjVu, Html Help and RTF document view.
Text viewer with syntax highlighting.
Folder comparison tool.
Text file comparison (difference) tool.
Hex viewer for binary files.
Web Browser for web and email files.
TTF Font files view.
XML structure view.
SE-Explorer is powerfull and easy tool which you can use everywhere – just copy application executable file to your USB flash drive and work with program on any PC.