Prestashop upgrading problem

[jerico.bd]

Hi,

I am using prestashop 1.6 and now I want  to do one click upgrade my site with prestashop 1.7 but i couldn't that. I already tried to do more then 4 times but I can’t, every time I got a massage form there .htssss file problem or something like that. And finally I got result, my server has been crushed unfortunately. That's why last 3 days nobody can't visit our site due to "HTTP ERROR 500" problem. Even I couldn't open my prestashop Dashboard panel too. At last our Provider told us a root folder has been missing from our server when we were trying to upgrade.

After then I had tried to install manually in my local host with xampp but I steel couldn't.  Plz let me know what the problem was?

Thanks,

Jashim Uddin