I want delete all files and reinstall vbulletin.

[blind-eddie]

Do not delete anything, yet.

First uninstall every thing you have installed properly including any uploaded files folders that came with them. It may take you some time but that is the nature of the beast.

Revert all templates that you have edited to take them back to default.

Doing as stated here will make your site like new without losing members or any threads/post.

What you are hoping you could do as stated in earlier post will open a big can of worms and give you many headaches and cause you to post here for help..... just do as I stated and you will be happy.