Optimize the compression process for ISO files.
Optimize the compression process for ISO files.
I've been experimenting with customizing my Windows ISO files. Since I generate many copies, I require extra storage and compression options. I also use NTLite, and occasionally pair it with the MSMG Toolkit. I realize I'm doing something unusual. First, I noticed that the original Windows ISO includes a WIM file, which I thought was an ESD file. It's about 5.58 GB, while the entire ISO is 6.33 GB. It's worth mentioning that one version with debloated files and integrated updates has a WIM size of 8.11 GB and an ISO size of 8.78 GB. But it only contains a single Windows edition, so the original ISO’s compression is quite tight. If I recall correctly, the full ISO with drivers and updates (no debloat) removes unnecessary editions, resulting in a WIM file of around 9.2 GB, while the complete ISO is 8.78 GB. Now using NTLite, I've recreated an ISO that serves as a backup copy—without the bloat, stripped down to essential editions and updates. This version has an ESD install file of 6.21 GB and an ISO size of 6.98 GB. What compression method does the original ISO come with? The WIM file indicates it’s already compressed, but I’m curious if further compression is possible without needing the full ISO. My current ISO contains only one edition plus updates and drivers, whereas the original packed everything into a single edition. Does this extra edition add significant space (though likely minimal after compression), or are the drivers and updates the main culprits? Drivers shouldn’t be overly large, and the compressed updates are around a gigabyte. I also planned to use 7-Zip for compression, but the savings didn’t justify it.
WIM files can be compressed with different codecs or algorithms. The method used by ntlite might use a faster or lighter compression, while tools like Wimlib support various options: https://wimlib.net/compression.html. I’m not certain every algorithm is included by default, and more advanced ones such as LZMA may not be available.
I expect minor variations between versions, meaning only unique files need storage. Removing an edition would delete data that stands out, which isn't expected to be much. I think the changes are mainly updates. It's likely original files should stay for internal checks during installation, so each release needs multiple copies (original, update 1, update 2, etc.). We can't say what compression method Microsoft uses in their installer, but you'll probably be limited to the ones they support.
So LZMS is the top choice? Besides the compression time, does it really slow things down significantly, or does decompressing take only a short time? When I load the original Windows ISO or my uncompressed version in NTLite, the performance seems similar, though I’m not entirely confident. I also have an old laptop with a hard drive nearby that I could use. I expect the Ethernet connection to be about 100 Mb/s, but I can’t directly access it.
A almost 9gb iso wtf. I would just install microwin and debloat the iso through that and you can do it through winutil as well as inject drivers if you wanted to and it makes it very small as well as fast. As for compressing well windows uses lzm for iso compression by default but you can use the LZX algo to get the most amount of saved space at the cost of it using lot of cpu resources while compressing afaik. Here is the command to do so, I have not tested this so do it at your own risk btw: Run this command in cmd as admin compact /c /s /a /i /exe:LZX "C:\path\to\your\file.iso" Here is the link if you want to read more about compression in win 11 and etc: https://www.elevenforum.com/t/compress-o...s-11.8775/ Hope this helps
You're wondering what results you should anticipate. A 6.98gb ISO reducing to just 4GB? That's not a trick, it's about understanding why the file size is so large initially. There are alternative methods you could explore, but they won't significantly change the outcome. You might want to check this resource: https://stackoverflow.com/questions/5849...ar-content