XSum Home

XSum: file checksum utility

Updated
17-Feb-2011

XSum is a freeware interactive program that quickly computes and maintains file checksum information.

Typical use cases are:

Verifying data intergrity on any disk-type media.
Visualizing time, size, and contents changes on a tree of files.
Ensuring that critical data are have not been changed a single bit.
Making sure that a disk duplication process performed a 100% one-to-one copy.
Assessing damage caused by a virus infection.

Latest Public Release / Download / Installation / Removal

Download Release 1.08.104
Self-check against check.sum
MD5 checksum: 9f82c411879d4e4ac4cf5a9cda13a8b5 *XSum.exe

The application does not have an install/uninstall procedure. Simply copy the .exe file to a convenient utility directory in your system (or make one under Program Files) and run it from there. To replace an older version, simply override it with a new one.

To completely remove all traces of XSum from a system, delete XSum.exe and optionally all .crx and .sum files. Then (using regedit or regedt32) delete following keys in the system registry:

HKEY_CURRENT_USER\Software\Hroch\XSum
HKEY_CLASSES_ROOT\.crx
HKEY_CLASSES_ROOT\.sum
HKEY_CLASSES_ROOT\XSum.Document

If the program was run under various users, you may have to remove registry entries from each user's profile.

The XSum utility (hereinafter the Software) may be used and distributed by anyone free of charge under the following conditions:

Any use of the Software is at own risk of the user.
The author will not be liable for any consequences arising out of use or inability to use the Software for any purpose.
The Software and any associated documentation may not be modified in any way.
No third party may charge any fee for use and/or distribution of the Software.

System Requirements

Intel Architecture (IA32) X86 - (Intel, AMD...; min 386) computer.
Screen resolution at least 800x600 pixels
Microsoft Windows 32-bit operating systems

Tested: 2000 Professional (NT5) all SPs, XP, XP/SP2
Assumed: 95, 95B, 98, 98SE, ME, NT4.

Release Notes & History

Release	Features and Bugfixes
1.08.104 19-Aug-2007	Now fully supports any UNICODE characters in file/directory names, encodes check.sum in ASCII or UTF-8 (if needed), decodes ASCII, UTF-8, ANSI, UCS-2. Non-critical file attribute flags no longer treated as modification. Tolerates comparisons over various file system time stamp granularities (e.g. NTFS vs. FAT vs. EXT2\|3/SMB). Fixed minor bug in freeze-mode and interface thread performance.
1.06.94 17-Jul-2006	Now fully supports UNC paths. Supports generic XP controls template (XP button look on Windows XP).
1.04.91 28-May-2005	Maintenance Release: greatly optimized internal handling (alas, not file scanning, which is CPU or disk-read limited) for very large data collections.
1.04.90 26-May-2005	New Freeze feature to temporarily halt lengthy scan to boost other applications' disk throughput (e.g. file copying). Spawned a separate thread to generate output file; improves user perception of response to a <Save> command. Fixed an intermittent bug: last file's status on list would not always update at the end of scan.
1.03.86 02-Aug-2003	Maintenance Release: Better Support for non-standard desktop colors.
1.03.80 31-Oct-2002	Sped up file list display by using virtual list control.
1.03.78 14-Jun-2002	Fixed a bug: Automatic column re-sizing is now invoked upon changing view criteria (e.g. view same, view error etc.).
1.03.77 17-Apr-2002	Fixed a bug: if only change is that files are missing as compared to recorded list, document is now marked modified at the end of directory scan.
1.03.76 17-Apr-2002	Introduced "Save and Close when Done" feature.
1.02.74 15-Apr-2002	Serialized scanning and CRCing phases of operation to optimize disk access Optimized (read: eliminated) display update during scan phase Lowered CRCing thread priority to ease XSum's load on the OS during long scan Spawning a worker thread for check.sum file parsing - does not freeze for minutes if loading thousands of files Added View... Follow scan capability (scrolling to most recent entry during CRC scan)
1.01.67 15-Oct-2001	Added support for NTFS file attributes: SPARSE_FILE (z), REPARSE_POINT (p), NOT_CONTENT_INDEXED (j).
1.01.66 11-Oct-2001	Fixed a bug causing XSum to always fully re-CRC whole list upon "Rescan New" command.
1.01.65 10-Oct-2001	Fixed a bug presenting an overal comparison result as SAME (unmodified) if the only difference was in CRC(s), as is the case with data damage. Previous releases did show the difference, but did not mark the whole document as modified in this specific case.
1.01.64 07-Oct-2001	Automatic machine signature of the output file (can be checked for integrity as it always yields ITU-V.42 CRC = 0). Automatic integrity self-check - XSum.exe program will refuse to run if modified (e.g. by a virus), giving a user a warning message.
1.01.61 05-Oct-2001	Changed name from CRCDir to XSum First web page support on HROCH.NET. Supports two suffixes .sum and .crx Default checksum file is check.sum, alternatively CRCDir.crx
1.01.59 30-Sep-2001	First public release

Known issues and planned features

Printing.
Difference sensing by category on/off (name, ext, date, attr, size, CRC).
Name pattern, size range, date/time range, attribute mask filters.
Pop a dialog box upon trying to close active scan.

Please e-mail the author with comments, suggestions, bug reports. Thanks.

A HROCH.NET document