After reinstalling Windows 7, problem with changing (single) user name

I had to reinstall W7 Pro X64 on my home PC to cure problems with sleep/hibernation.

After reinstalling, I found a single user account had been created named "DELL".

All my previous software (now stored in Windows.Old) referred to user name "Brian". So I changed the name of the DELL account to "Brian". But I then found that although the user folders are sometimes shown as "Brian", at others they are shown as "DELL".

How do I make the change of account name effective for all the relevant user folders? There is no facility to rename C:\Users\DELL; is there some other way?

Rich is right.
Same happened to me, I've initially misspelled the username & subsequently the user folder name on a brand new system and wanted to rename it.. Even if You change the username, which You can, the folder name for some reason doesn't change automatically. And You can't rename User folder, only create new one. So I've made a new administrator username & folder, logged in with that new one & deleted the old.. Beware though, it was easier for me on a brand new system as I had no data, You need to make sure that You have transfered all Your files, including hidden system files if there are any, from the old account to new one.. so just make sure You have transfered everything.

This is for security reasons that only MS seems to know. It won't change User folder name at root.

If this bothers you I would clean reinstall following the steps in my signature picture below to get a flawless reinstall based on thousands done here.