System drive space doubled in size within the past month.

I am using a 128GB SSD as a dedicated windows boot drive. Data is stored on other drives. The current size of my Windows 10 installation is 42Gb. Before removing hiberfil.sys, pagefile.sys, temp files, and System Volume Information files, (including System Restore files), the size was 51Gb.

Prior to this month, the same installation and previous v2004 installations of the past year, were always between 22Gb and 25Gb.

Scans with Windows Defender, Malwarebytes, and ESET online scan, were clean.

The installed apps were always the same. What could cause such a recent bloat?

Hello @ineuw,

ineuw said:

I am using a 128GB SSD as a dedicated windows boot drive. Data is stored on other drives. The current size of my Windows 10 installation is 42Gb. Before removing hiberfil.sys, pagefile.sys, temp files, and System Volume Information files, (including System Restore files), the size was 51Gb.

Prior to this month, the same installation and previous v2004 installations of the past year, were always between 22Gb and 25Gb.

Scans with Windows Defender, Malwarebytes, and ESET online scan, were clean.

The installed apps were always the same. What could cause such a recent bloat?

Have you got a Windows.old folder?

> What is Windows.old Folder and How to Delete Windows.old Folder in Windows 10

I hope this helps.

Hello @ineuw,

You could try and see what is using the MOST SSD space . . .

> WizTree- The FASTEST Disk Space Analyser

I hope this helps.

There is no Windows.old. Thanks for both software recommendations. Downloaded and used them both. BTW, there was no Windows bloatware in the quoted sizes. Removed everything except MS Edge and a few small utilities. Also unininstalled Gimp because it grew to be 1.1Gb. So the current OS size is 38Gb.

I also kept a mirror of the original 2020-11-06 installation . The mirror was made after Microsoft completed the update, and without any apps. The size of this mirror is 11.2Gb. I could restore it, let Windows update it, create a new mirror for safekeeping, and then install my apps and see what happens. Any thoughts?

ineuw said:

What could cause such a recent bloat?

One user has recently reported that reserved storage was taking up to 50GB, so it is worth checking out.

Enable or Disable Reserved Storage in Windows 10

Matthew Wai said:

It's worth a try. My Windows 10 Version 20H2.

Meaning that I should re-install?

Hello @ineuw,

Please look at TairikuOkami's suggestion above first, he makes a good point.

Paul, is Windows 10 reserved storage the same as Windows 7 system restore point storage?