First I got the redirected too many times. On clearing the cache and putting in the address bar sitename/index.php I got the start of the install.
I copied into place on the server the config.php file as I have done many, many times before and clicked continue. Then I got redirected too many times again.
Having scoured the help - I have cleared the browser cache and cookies, I've cleared the Moodle data folder cache. I've checked the php server settings for max execution and memory limit. I've tried to put the debug section in the config file - if it is working then it is displaying nothing that I can find.
If I put an extra forward slash onto the site name in the config file it tells me the site is badly configured etc. so I know it is reading the config file. (I've taken that out again and re-cleared the Cache, stopped the application pool and the web site).
I have even tried commenting out one of the redirects in the index.php file as per one of the video suggestions on this site - didn't work either.
All the info I've been reading is suggesting that it is the log in page that is the culprit and some of the suggestion are to go directly to specific pages - I can't do that because I haven't created an account yet to log in with, my install didn't get that far it fell over after the config.php but before the make an admin account.
Any ideas what to try now please?