Cannot access webmin admin cannot delete old files

I became unable to access the admin account after amending the wordpress URL, after attempting to get my host server to show page themes and graphics on my blog site. I have deleted the my wordpress and the IIS Express files and the remote host files to clear everything, but evrertime i reinstall i get the same local host with no web admin access and even the local host blog will not load themes.

How do i get rid of the old blog and install a new one to allow me to access the webadmin to start dealing with the issue.

I am using webmatrix…..