Unicode grep for Windows

For a command line tool, look at KeyboardMonkey answer (but I'm not sure about Unicode support).

For an (open source) GUI tool: dnGREP

• Shell integration (ability to search from Windows Explorer)
• Plain text, regular expression, and XPath search (including case-insensitive search)
• Phonetic search (using Bitap and Needleman-Wunch algorithms)
• File move/copy/delete actions
• Search inside archives / MS Word documents / PDF documents (via plug-ins)
• Undo functionality
• Optional integration with text editor (like Notepad++)
• Bookmarks (ability to save regular expression searches for the future)
• Pattern test form
• Search result highlighting
• Does not require installation (can be run from a USB drive)

For a more simple (only search) GUI tool: AstroGrep and for a more featured (and expensive) one: PowerGREP

Most versions of Windows include the command "findstr" which works much like grep. I do not know about its Unicode abilities, but to my knowledge there shouldn't be any problems with that.

Update: GnuWin32 is a more recently maintained port of these tools. (Thanks Quack)

Here is a list of the packages and to download grep individually.

Have a look at UnxUtils, which includes grep as well. I use these on my work PC, too.