Will updating our site from ASP .NET 3.5 to ASP .NET 4.0 negatively affect SEO?

[FreightTEK]

I've checked out some of the other posts related to .NET upgrades, but none specifically address ASP .NET 4.0.

I understand that there are many advantages to upgrading, but as with any change made to site code I want to be 110% positive that this upgrade will not affect how Google ranks my client's pages.

Since the URL extension isn't changing (will remain .aspx), I'm thinking that there won't be much of an affect on SEO at all. In fact, I'm making the argument that the upgrade will only improve page rank.

Anyone go through this upgrade and experience any immediate benefits or disadvantages?

Thanks for your help!

[Bromtec]

If your ASP code is used primarily for dynamically generating HTML (at or before page load), and the HTML isn't changing, and your URLs are staying the same, I can't see how SEO would be affected or why you'd run into any problems.

If the upgrade includes code modifications that change the way the pages load, however, it could affect SEO depending on how that's handled.