ubuntu - Can’t make partition on 500 GB SSD on Windows 10

I want to make a new partition of 100 GB for installing Ubuntu on a 500 GB SSD, and I have about 150 GB free space in my C: partition (running Windows 10 OS), so I'm trying to shrink it.

But Windows Disk Manager says that I can shrink no more than 326 MB, which is too little to install another system.

Here's a screenshot from Windows Disk Manager:

It says that it can't shrink more
because \pagefile.sys::$DATA is unmovable:

So I turned off paging on disk C:,
but still I can shrink no more than 326 MB from C:.

UPDATE:
Defragmentation of disk was needed, it gave me about 32 GB place to shrink more.
Now I have porblem with anoother unmovable file
\System Volume Information{...long_hex_value...}{...long_hex_value...}::$DATA

What could cause this? How can I move my unmovable file(s)?  How can I make a partition on my SSD for installation of another system?

UPDATE
Memomory problem solved. Just needed:

https://www.disk-partition.com/disk-management/unable-to-shrink-c-drive-0310.html

Disable System protection:Press “Win + R”< enter “SystemProperitiesProtecion.exe”< press “Enter”< click C drive< click “Configure”< select “Disable system protection”< click “Apply”< click “Yes”

Disable Hibernation:Click “Start”< type “CMD” in the Search box< right click “cmd”< choose “Run as administrator”< enter “powercfg.exe /hibernate off”

Disable Page files: Press “Win + R”< type “SystemPropertiesPerformance.exe”< Press “Enter”< click “Advanced” < click “Change under Virtual Memory”< uncheck “Automatically manage paging file size for all drives”< click C drive< set paging file size to No paging file< click “Set” < click “OK”< restart

Disable the kernel memory dump:Click “Start”< select “Control Panel”< click “System and Security”

Notice: You can restart computer after all the above set.

Unfortunately even though I got 133 GB free space to shrink, when I try to shrink even small disk amounts like 10 GB, disk manageres processes something for few minutes and then says, not enough space to shrink. Then if I check availble space to shrink it says i have 130 GB. Do not have ideas what to do now...