Reinstalling windows 10 on the same hdd

[Cmei5686]

Recently my HDD has become slow, I was wondering if I need to wipe all the data from my HDD before reinstalling windows on it or can I just boot up windows installation from my USB and overwritten the previous windows and data on my hdd

 

[Colif]

Fresh install wipes hdd anyway

follow this guide: http://www.tenforums.com/tutorials/1950-windows-10-clean-install.html

when you reach the screen asking for licence, click "I don't have a key" and win 10 will continue to install and reactivate once finished

On the screen where you choose where to install win 10, if it gives you an error about GPT drives, delete all the partitions on the hdd and press next. If it still gives error, cancel out of the installer and restart PC and start installer again, it will accept next on that screen this time (some PC just need a restart here)

 

[V1ctor89]

You can use HDShredder to zero-fill the HDD, this will rejuvenate the cells on the platters and improve the overall health. Careful! That software needs to be booted up. It will erase everything on the HDD, make sure u backup everything essential first.