Is there a simple way to change name?

I am a complete WP newbie so making lots of rooky errors!

I foolishly installed WP to a folder called wordpress and set up my database laetestsite before I realised that would mean it would appear as https://localhost/wordpress instead of https://localhost/laetestsite.

I tried just renaming the folder but obviously not as simple as that as it then finds localhost/laetestsite correctly but the home page displays as a plain HTML format instead of with any kind of layout or theme. Also displays error 404 every time you try to access another page or even log on to admin.

Works fine again once I change the folder name back so I am assuming that this must be recorded in a set-up file somewhere. Is there a simple way to manually amend this so wordpress looks in the correct place or am I stuck with a complete reinstall?

I have installed locally on a windows 7 machine and am using xampp and apache.

Thanks for any suggestions.