Full format of my 'C' Drive

I am just about to do a re-install of Windows 10 and am wondering if I can first do a very thorough clean-up of my 'C' drive first by doing a full format before carrying our the reinstall.

I am just about to look for the USB stick with Windows 10 on it, I think that it must be 12 months old by now, is it OK to use this or would I be better off downloading a more recent version.

Many thanks.

When you get to the custom install screen with all the existing partitions listed, you can delete each one and then select the unallocated space to install to and click next. If you have a data only partition that you want to keep, then don't delete that one but still select the unallocated space to install to. If you do have a data only partition, hopefully it is at the very end of the hard drive so you don't end up with wasted space after it.

Thanks for the replies folks.
I have now made a new USB with the latest Windows which I got from the link given above.

I have been using Microsoft Outlook since I changed to Windows 10, Can you tell me if I will lose my emails when I do the reinstall?
Are you going to tell me that I will need to save each of them to a folder before I do it?

Brink said:

If you have your emails set to keep a copy on the email server, then your emails will sync back when you set up Outlook with the email account again.

Hello Brink, thank you for your input. This is not something that I am aware of, how can I check to see if it is set up that way and, if it's not, can I do it now or, will it only save any new mails from the time the setting was changed?

Brink said:

If you have an @Outlook.com email address, then it syncs by default.

No unfortunately mine is an @gmail.com

Thank you Brink, I think that I should be OK.