5 GB just disappeared, how to get it back? (TrustedInstaller involved)

I have a ThinkPad X220 with a 120GB hard drive.

Yesterday, I used "Disk Cleanup" on the Properties page of the C drive (via Windows Explorer) and it freed up about 1GB, the resulting "Free Space" being 60.5 GB (as shown on the same Properties page).

Today, I did it again, thinking that it wouldn't do much, because I had just done it yesterday. The cleanup completed quickly this time, but at the same time, I noticed the Free Space number mysteriously going down, and it kept doing that for several minutes (even after the Disk Cleanup UI seemed to have finished). I looked at Task Manager and noticed "TrustedInstaller.exe" running, which seemed odd, because I wasn't installing anything.

At some point, I decided to do a Shut down. It said something about a Windows update running, 30% complete. Not sure why, as I didn't ask for any update. Then the shut down completed (i.e., the computer was off). Then I started it up, and it went to a screen saying update in progress, don't turn off the computer. After this went on for 5 or 10 minutes, I figured something must be wrong, so I held down the power button to shut down, and it did. On starting up again, it showed the white-on-black text screen saying Windows was not shut down properly, and I chose Safe Mode with Command Prompt. Then it didn't do that, it just restarted and then went to a screen saying the update failed, reverting... which I thought was fine, because I have no idea what it was doing, and whatever it was, I wanted it reverted. Again, it said don't shut down, so this time I let it run its course, and it eventually booted up into Windows.

This is when I noticed that 5 gigabytes had disappeared, as the Properties page for the C drive now shows Free Space as 55.5GB. 5GB have disappeared!

I'm astounded that the system can do such things that I didn't ask for.

How do I get my 5 gigabytes back?

Hi

from what i can find that comp comes with W10...

UNLESS you installed an upto date W7, including ESU, image then it will update.... a W7 SP1 will install about 200 updates afterwards
hence the loss of space

torchwood said:

from what i can find that comp comes with W10...

I bought it used 4.5 years ago from a shop that sells and repairs computers. It came with Win7 SP1 and I haven't changed the OS since.

UNLESS you installed an upto date W7, including ESU, image then it will update.... a W7 SP1 will install about 200 updates afterwards
hence the loss of space

Does that mean everyone with Win7 got an update consuming 5 gig on Dec. 2? Since it didn't update before that, and I didn't push any button to initiate it, I can't see why it did that on Dec. 2, unless that's when the update was released.

Last but not least, in situations like this, is there any way to examine my system to find out what actually happened? As it stands, I have no way to tell if the 5 gigabytes was consumed by an ESU, or by malware, or by a system malfunction, or by me pressing the wrong button (like initiating a massive copy operation that I didn't want, or whatever).

- - - Updated - - -

This is interesting. This evening (about 20 hours after) I find that the 5 GB is back. The Free Space on C drive now says 60.5 again.

So that's good news... but I keep wondering if there's something I can look at on my system to tell what it's doing.

hi

there's a program called TreeSize.. that analyse's the folders

The missing space comes and goes to virtual memory file (C:\pagefile.sys). It is a system hidden file so to see it you must enable to see system hidden files on Explorer options.

Megahertz07 said:

The missing space comes and goes to virtual memory file (C:\pagefile.sys). It is a system hidden file so to see it you must enable to see system hidden files on Explorer options.

OK thanks. As I mentioned above, I did notice that several gigabytes of free space seem to come and go. I eventually figured out that it's being consumed by Mozilla Firefox when I have a lot of tabs open, and it gets released later when I shut it down (or some time thereafter).

Exploring further, especially under C:\Users\(username), I figured out that several more gigabytes were being consumed by old garbage files. This includes cache files from Firefox (even though I had it set to private browsing mode, which supposedly deletes history upon closing) and Chrome. Clearing history in both Firefox and Chrome freed up a lot of space. In Firefox, I had to do that across multiple "profiles" that I forgot were there. I also found out that in Firefox, instead of setting private browsing mode, it's better to set custom history options and check the box for delete history on closing.
I never figured out what "TrustedInstaller" was doing, I guess it just chose that moment to try some kind of update, which increased the sense of mystery for me.

Thanks to all, I think I have my disk space under control.