Moving a Established Site From .htm to .aspx

How do the search engines handle a upgrade of a site

[Aberdeen]

We are thinking of upgrading our main site (which has a Page Rank of 5) up to a database driven site using .aspx . How will this effect our google rankings? How quickly will it come back the same ranking, as we are #1 for our keyword, and fought hard to get there? Will it be months or years etc.

I am sure many people have been through the same experience, so advice would be great.

Cheers.

[bilalak]

First of all, Try to emulate your new pages to be as static looking as possible.

Second, do not delete old pages or try to map old URLS to new files with 302 response.

Third, Try to modify the incoming links to reflect new URLs. Forwarding with a 302 only would not keep the same PR

Fourth, Try to get the best and simplest site structure for a crawler to get all your internal pages easily

Fifth, maybe an aspx extension is not the best to use. Emulate with html.

Luck!