ClamWin is a Free Antivirus for Microsoft Windows 98/Me/2000/XP and 2003.

ClamWin Free Antivirus comes with an easy installer and open source code. You may download and use it absolutely free of charge. It features:
High detection rates for viruses and spyware;
Scanning Scheduler;
Automatic downloads of regularly updated Virus Database.
Standalone virus scanner and right-click menu integration to Microsoft Windows Explorer;
Addin to Microsoft Outlook to remove virus-infected attachments automatically.

ClamWin Free Antivirus features:
- High detection rates for viruses and spyware;
- Scanning Scheduler;
- Automatic downloads of Virus Database updates. ClamAV team regularly updates Virus Databases to include a new virus/variant immediately after it appears;
- Standalone Virus Scanner;
- Right-Click Menu Integration to Microsoft Windows Explorer;
- Addin to Microsoft Outlook to remove virus-infected attachments automatically. Built-in support for mbox, Maildir and raw mail files
- Built-in support for RAR (2.0), Zip, Gzip, Bzip2, Tar, MS OLE2, MS Cabinet files, MS CHM (Compressed HTML), MS SZDD
- Built-in support for Portable Executable files compressed with UPX, FSG, and Petite

* Bugfixes and changes since 0.91.1:
- libclamav/rtf.c: fix possible NULL dereference bb#611)
- libclamav/ole2_extract.c: properly initialise hdr.max_block_no (bb#603)
- libclamav/htmlnorm.c: fix possible NULL dereference (bb#582), thanks to Stefanos Stamatis
- libclamav/htmlnorm.c: fix call to tolower() (bb#580)
- libclamav/filetypes.c: some embedded PEs were not being detected
- clamav-milter: Fix compilation error on NetBSD2.0
- clamav-milter: Black-hole-mode no longer needs to be run as root
- libclamav/pdf.c: Bug 618, --block-max not always honoured
- libclamav/phishcheck.c, regex_list.c, phish_whitelist.c: make debug output look better (patch from Sven)
- libclamav/phishcheck.c: Don't report phishing on broken urls containing '>' in the hostname. (bb #619)
- libclamav, sigtool: add support for PUA databases (.hdu, .mdu, .ndu), requested by Christoph
- clamscan: add --detect-pua
- clamd, clamd.conf: add DetectPUA
- freshclam/mirman.c: properly handle mirror access times (bb#606, only outdated installations - three versions behind the latest one were affected by this problem), Reported by David F. Skoll
- clamav-milter: Bug 614
- libclamav/pdf.c: Bug 608
- clamav-milter: SPF checking no longer experimental
- libclamav/phishcheck.c: workaround Solaris problem with regexec() [bb #598]
- libclamav/matcher-ac.c: fix matching of patterns with prefixes and some other issues spotted by Glen
- clamav-milter/clamav-milter.c: Better use of res_init()
- clamav-milter/clamav-milter.c: HP-UX doesn't have EX_CONFIG, reported by clam * ministry.se