When you hive off your data to a separate partition or drive, you may have issues accessing your user folders after reinstalling Windows. That’s because they’re ‘owned’ by your current user account, and when you reinstall Windows, you’ll end up creating a new user account, even if it’s identical to your old one.
In most cases, when you first try to access one of these folders – when you point Windows toward them, say – you’re told access is denied, but are prompted to click Continue to gain permanent access. This usually resolves the issue, adding your current user account to the list of users who have been permitted access. If this fails, you need to manually take control of the folder. Right-click it, and choose Properties, then the Security tab. If there aren’t any read permissions, click Advanced, followed by Continue. Next, click Add, followed by ‘Select a principal’, before clicking Advanced > Find Now.
You have a choice – if you share your PC with others, select your username; if you’re the only user, you could select ‘Everyone’, which saves the hassle of having to repeat this process every time you reinstall Windows, although if it’s a laptop, ask yourself if you want the data accessible to anyone who might steal it. Click ‘OK’ twice, and you should now be able to assign basic permissions – choose Full Control if you were the previous owner of the folder. Click ‘OK’, select ‘Replace all child objects’, and click Apply > OK. Click ‘OK’ twice, and you should now have access. If you’re feeling zealous, right-click the folder again, and choose Properties, then the Security tab. Click ‘Edit’, then select each ‘Account unknown’ entry – a reference to earlier Windows installations – and click Remove followed by OK to get rid of them all.