I have created my pages in asp.net previously it was in asp and now my previous site should be replaced by asp .net. Now my question is that my previous site has Pr=4 wen i replaced it into asp.net is its Pr changes or should remain the same???
If the urls change, you're starting from scratch, even if it's just the last part of the url that changes e.g from yoursite/page.asp to yoursite/page.asp.net - Unless - you put a 301 redirect in place from the old pages to the new pages.
In case your website domain is going to change then you should other about PR. If everything is same, i mean all URL and sub-domain should be same, there is no problem with PR.
Your case is sensitive many time people face this problem after do change their site so this case more chance to get lose your PR even if your domin if change because Google some time penalty the user those do change
first redirect your old page on new page. use 301 redirection and also not change in content or linking. after 3 month next google update PR that time u got back result. i had experience with my signature website same your type
I don't think he is concerning anything about SERP's. So how contents are going to play any role in PR? I have never heard that contents play any role in increasing your PR. Nor even he is trying to change his contents. The thing is that he is trying to change his designing. Anyhow, there is no connection that redirects and changing website design. This only comes in action when he would have been thinking to change domain on old website. I am sorry but i cannot understand your post !!