How to gain the lost ranking(due to site redesigning)of a site?

[Abirami]

I had a site designed in ASP.net and it had good rankings in Google. Then due to the plan of the management, the site has been redesigned and now it is a HTML site.

There is no change in the domain name. File names are changed and the number of pages are increased. Without doing any redirection, the old files are abruptly removed and new pages are uploaded. New sitemap has been created and linked with webmaster.

Now the ranking on Google has been drastically reduced.

Is there any way to regain the ranking that is lost? Is it possible now to redirect pages from old asp site to new html site?

Please suggest me ideas to improve the ranking for the new site.
Is it possible to upload the old site's ASP pages and then redirect them to HTML pages?
If done so, Will it help to regain the ranking?

[sabari]

by some SEO techniques like

article submission
pressrelease submission
bookmarking
directory submision

[Peter Nikolow]

Yes - this is HUGE mistake from management. You need to redirect all pages from old site to new site using 301 redirects. I repeat - ALL pages.

This will help search engines to stop losing ranking and can gain ranking. Please look on link how you can do it for single page.

[Deepika]

there are many to available to improve google ranking like blog comments,article submission, forum participation,profile link and social media sharing.

[Aaliyah]

Use 301 redirect on your sites URL and first you do search engine submission then do others process of SEO.

Because by search engine submission your website again crawled by Google in some days then you get ranking effect by other process.