I did a backup of Windows 10 with Macrium Reflect. Previously the image was around 14GB but now it is 43GB and I haven't since then added anything else to the OS disk. Where did the rest come from? The free space is still same as when the image was 14GB.
I think I did create the rescue media wrong. I think I had selected PE version for Windows 7. I create it again but with PE version for Windows 10 and it worked like it supposed to do.
Hello @WinFree - Did you alter any of Macrium Reflect's default settings before you created the second backup image? There are two things to double-check. Click the "Other Tasks" tab and select "Edit Defaults". You should find panel for the Default Compression Level Settings are already displayed. The first thing to check is whether the Compression Level is set to None, Medium (Recommended), or High. I've found that using the Medium setting reduces the size of the backup image by about 30-35% compared to using None. The second thing to check is whether you're using Intelligent Sector Copy or making an exact copy of your Windows disk partitions. If you're making an exact copy, you're including the system hibernation file (hiberfil.sys), the system paging file (pagefile.sys), and your system restore points (volume shadow copies stored in the hidden folder System Volume Information). If you include these three things in your backup image, it could account for the additional 29GB you're seeing. Also, I've read that making an exact copy will include any deleted files that have not been overwritten.
I did not made any changes when I was inside but there is a option to do some changes just before you do the backup. There I had the option to change compression level and sector copy or exact copy. I selected no compression since it's only 14GB and selected also sector copy. This way the backup size got only 14GB. I did the same thing the first time. Second time I downloaded the updated version and when creating Rescue Media I changed PE version to Windows 10. I think the first it was PE version for WIndows 7 because it's selected by default and forgot to change the settings there. Second time I changed that to Windows 10 but I don't have a clue if that was the issue?