Before modifying your database please do a backup of it first.
Look at your database (phpMyAdmin). Look at ps_modules (or whatever your prefix is) and order by 'name', look for autoupgrade in the 'name'. Note the 'id_module' field, then delete that entry if you find it. Next, assuming you found the autoupgrade module in the previous step, look at ps_module_access, order by 'id_module', delete all three entries that correspond to the autoupgrade modules 'id_module'. Next...look at ps_module_group, and sort by 'id_module' you should find 4 entries with the same id as the module, delete them.