Will deleting Windows.old cause issues?

[mckevstah]

So my Win10 install was working fine and then a few days ago it just buckled and I had to do a reset (New OS, but keeps personal files)

For some reason the Windows.old folder is 420GB.
When it transferred my files over to my new OS, did it just copy them? Will deleting the Windows.old folder affect any of the files that carried over?

 

[basroil]

Looks like there's a typo there! 8-40GB i could understand, 420?

Just run the disk cleaner in administrator mode and select the option to remove previous install files. You can do it yourself, but disk cleaner method will also let you clean up everything else at the same time.

 

[Slashgeek]

Deleting Windows.old will not affect anything as a rule, but you might find some personal files in C:\Windows.old\Users.

 

[Dunlop0078]

In theory deleting the window.old folder should be just fine to do. However I was in your exact same position I deleted my windows.old folder to free up some space then the next time I turned on my computer it wouldn't boot had to run startup repair to fix it. I believe it had something to do with my SSHD keeping files in windows.old that it needed or something I believe a normal hard drive wouldn't have this problem but im not sure here is my post about it if your interested.

http://www.tomshardware.com/forum/id-2777222/deleted-windows-wont-boot.html

 

[mckevstah]

Okay thanks guys, disk cleaner, is that 3rd party or a windows app?

 

[Dunlop0078]

Okay thanks guys, disk cleaner, is that 3rd party or a windows app?

Disk cleanup is a windows tool. However I use the thrid party tool CCleaner for disk cleanup.

 

[0xBahaa]

Okay thanks guys, disk cleaner, is that 3rd party or a windows app?

Windows "disk cleanup" utility

 

[Dogsnake]

This file is there for restoring your previous version of windows if needed. When you delete it you will give up the ability to roll back in case you want to. The roll back option is good for only 30 Days. After that it is unclear how you would return to the previous OS (http://www.extremetech.com/computing/211557-reminder-windows-10-rollback-option-is-only-available-for-30-days). If a roll back is not of any concern to you then you can delete that folder. It will have no effect on the current Win10 installation.

 

[0xBahaa]

Also, if u dont want to delete the whole folder, u can download TreeSize free and use it to inspect the C:\ partition. It will show u the exact space taken by each folder in descending order. You can use it to look inside the windows.old to see which folders in particular are taking much space (they will probably be folders containing backups of ur data), so if u have no need for those folders in particular, u can delete them. This is guaranteed to free up most of the space.

 

[mckevstah]

It seems to have cleared itself. That was weird. It's down to like 3gbs now. I have no idea what happened there. Thanks for replies everyone