Sethioz' Unstoppable Copier (freeware)
Written in python, inspired by Roadkil's Unstoppable Copier. I have used RUC many times and it has helped me recover some files from bad HDDs where other tools failed, but RUC has issue where it keeps freezing while processing large amount of files and it never unfreezes and it can also look bit overwhelming for average users, I wanted a simple, powerful, efficient and non-freezing type of copy tool, which is why i made SUC .. yes i know, the name, but i decided to leave it for the sake of it, isn't it striking?
FEATURES:
Works faster and more efficiently than windows default copy (very fast with "copy without scanning" mode).
Compares files by size+date modified, or checksum before copying (only overwrites, if different)
Can copy files with zero-fill recovery for corrupt data (good for partially recovering corrupt media files)
Supports resume of interrupted sessions
Uses Robocopy for speed or Python copy for reliability and precision.
Handles locked files more aggressively if needed or skips+continues if unable to copy for some reason (kernel/system locked files).
Configurable retry and logging options
Cancel button that actually works (forcefully terminates copy process if stuck)
Auto-cleans old sessions
Detailed progress, debug and error reporting available
Does not stop on errors (skips if not possible to copy, logs errors and continues)
No interaction / care needed once copy progress has started (Unstoppable)
NOTE: Requires admin privileges in most cases. (right click > run as admin).
It's designed for ease of use and comfort, while giving you decent amount of control over how it operates.
I have not fully tested each feature, but I did run enough checks to know that most important features work as intended. I tested it against locked files, like kernel-locked files in windows, such as registry files and such, which is where normal copy tools would poop-out and spit out ton of errors, but SUC won't nag at you and it won't stop on errors, hence the name - UNSTOPPABLE copier. If there are errors, then it will skip those files and log errors and moves on. I also simulated corrupt / tampered file copying to test checksum feature, I made 2 identical files with same name, but i HEX edited one of them and changed few bytes, so filesize and date modified remained same, but checksum was different due changed bytes. Then i used python copy mode + checksum compare and it was able to detect the corrupt file and copy it over based on checksum, while when using robocopy, it didn't overwrite the file as it only checked filesize+date modified. Keep in mind that checksum method is slower and even slower on large files.
Checksum method doesn't exist in most copy tools as they rely on filename + filesize + date modified, so if you had some malware that embedded itself into legit files without changing their size nor date modified, then most other tools wouldn't detect those files, but that's where SUC is better, it runs a checksum check on files and determines if they're truly identical or not. If they're different, it will overwrite destination file with source file.
DISCLAIMER:
It's freeware and you may share it, but I would much appreciate if you'd rather share this post than giving the tool to someone directly. You may host it on your own website/server if you include link to this post as original source (I may also update it in future and updates will be included in this post).
I take no responsibility for data loss or damage caused by misuse. Always double‑check your source and destination folders before copying.
SUC never modifies source files and is safe for use with sensitive/system data. It stores no hidden data on your PC. It only makes /sessions/ folder in its own working directory (where .exe is), containing human‑readable log/debug/session .txt files.
KNOWN BUGS:
Visual bug with progress bar, i can't be arsed to fix it as it's rather simple-complicated. Issue is that when you use "copy without scanning", then SUC is not aware of how many files there are to copy, therefore it can't show progress bar. It's like driving on a road and not knowing how long the road is, then you can't say "i'm half way there", because you don't know how long the road is. I left it as it is, cuz trying to fix it, may introduce other bugs.
Some visual theme issues may exist, but looks good enough for me, this is not suppose to be visual master piece.
Does not copy system / kernel or other hard-locked files. For this to work, I'd have to resort to VSS (Volume Shadow copy Service) and it's not that simple to implement it into a python script. If you want to make shadow copy of entire drive or volume, then look up tool called "drive snapshot".