If I remove windows old

Recently I had a Microsoft tech do an in place upgrade with media creation tool. it made a folder called windows old if i remove it from Disc clean up where it says previous installation will I lose what i have now like my desk top i cons, my programs, apps ,etc. I am trying to get that disc space back. Please advise I was afraid to do it. I tried to do it from the file itself but It denies me access and I do not know how to grant the access . All I want to to is get my disc space back. Thank you in advance I am using windows 10. Like I said i was / am afraid to do the above options for fear of losing everything. Thanks Mary

after i delete this will i need to reinstall or configure windows again or will it just sart normally like it is now will i get a screen asking me to safe files and such

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will it free up disc space so o will not lose aps programs and anything else will i need to start from scratch

thank you so much and when it gets deleted will i get the space back

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thank you all for your help on this now i have a different dilemma Some how I can not install or reinstall support assist. I usually disable or stop all the dell support assist and dell apps in as services . I tried to start dell client management got a error message and then tried enabling the rest of the Dell apps in services like dell data vault support assist etc and nothing worked so i went to uninstall it and it would not uninstall so I used Revo uninstaller and then rebooted tried to reinstall support assist and it failed every time tried. I finally called tel tech support and he tried everything even do 2 more test accounts and it would not install. I am not sure if it is the App itself a windows update or that the in place upgrade had something to do with it. Bi had done every thin that everon suggested but nothing