do you mean to say that the address:
is returning a 404 error? or what exactly do you men by:
Have tried localhost/Modular/PowerStores_Files/admin, no good.
in what way is it no good?
if it gives a 404 error, double check the file system for the correct folder name.
for example, using windows, and XAMPP, the localhost folder is ussually at:
go to that folder to look in the Modular folder and find the folder name that was used for the power store installation.