problems with server

@osvit said:

I have a problem with free hosting….

That’s the problem: free hosting. Get real hosting and you will have far fewer problems, esp. with losing data. See Recommended WordPress Web Hosting

Or use http://en.wordpress.com

You can install themes (in the control panel under Apprearance) but you can’t upload custom themes. No plugins though, not of the free side.

This page outlines the differences between the the wordpress.com’s free hosting and self hosting:
http://en.support.wordpress.com/com-vs-org/

Hope that helps.