Using existing database to install onto same domain but fresh install

Hi
I have an issue.
I had a perfectly running site.
I updated some plugins everything good.
I updated eShop would not work. Fatal Error to do with memory above 32mb. my php.ini is set to 40mb and cannot be increased.
Deactivated all plugins. Still no joy.
Rolled it back to a previous version. No joy.
Contacted plugin person and he kept pointing me to a memory issue.
Installed his plugin and all the other plugins on another site and everything worked fine.
I think something went wrong during the update of eShop.
I now have a site which will not work with eShop which I need.
This site is live.
I want to keep the database and try installing it afresh and was wondereing if i renamed the folder the domain points to and created a fresh install and then installed all the plugins would this work? Is there something I should know before doing this?
Is there something else I can try?
I know now i should have taken a backup of the databse before updating but I have never had an issue before.. i know its no excuse and I have learnt the ahrd way.. Any help would be appreciated… thanks
Mat