Disc out of space cleanup doesnt help

[Patrik21]

My c drive(916Gb) is full and cleanup doesnt help. I manage to remove some programs and get some MB back but it automatically fills up again. Some programs is not possible to remove at all, due to little free space it says. I have tried cleanup, defrag restarted etc. Nothing works, i believe i have some kind of virus. The drive toggles from 0 byte up to a few hundred MB free. I have had no virusprotection and trie to install Bit defender but it cant be installed due to lack of free space..

/Patrik

[TheOldMan]

If the system is infected to the point of no return, then replace the hard drive with a new clean drive and install Windows 10 fresh.  Since you are not in the USA, this link may not work for,  but there should be one in your area.  Use Google to find the correct one, if this link does not yield good results.  It is called the Microsoft media creation tool.

https://www.microsoft.com/en-us/software-download/windows10

With a working PC, scroll down to the "Using the tool to create installation media"
and then follow the directions. You can make either the DVD or USB.  Then use this new media to install Windows.

If you wish to try to rid the system of malware before replacing the hard drive and installing Windows fresh, see here:

https://www.howtogeek.com/175234/how-to-use-an-antivirus-boot-disc-or-usb-drive-to-ensure-your-compu...

It might be a good idea to run Windows Defender, built into Windows, after the new install of Windows is completed.  It is free and better than running without any antivirus software.

[WAWood]

@Patrik21 

You're certainly free to reinstall Windows or use an AV product -- as @TheOldMan suggested, although I would go for the latter, first.

But it does not to me sound like a virus infection -- just symptoms of a PC lacking the free space needed for Windows to work properly.

Here are some things you can do to recover some of the disk space:
http://www.tenforums.com/tutorials/3012-disk-cleanup-open-use-windows-10-a.html
http://winaero.com/blog/how-to-clean-up-winsxs-folder-in-windows-10/

Also, the community Win10 Forums has the following suggestions:
https://www.tenforums.com/tutorials/83441-free-up-drive-space-windows-10-a.html

In addition, I have found the utility Cleanmgr+ to have LOTS of options for removing Windows junk, including log files. I use it practically every day. You can get it from here:
https://www.mirinsoft.com/cleanmgrplus

Also, there is a freeware app known as Wise Disk Cleaner. I use it every day to get rid of junk files: https://www.wisecleaner.com/wise-disk-cleaner.html