So it works with the old router.

Why would you work on your PC if the new router is what changed?

For example, in your past you learned about Control Groups (http://chemistry.about.com/od/chemistryterminology/a/What-Is-A-Control-Group.htm ) and you change one thing at a time to see where the issue is.

Here you changed the router but then began tinkering with the PC instead of the router.
Maybe there's more to this story but as it stands, it's not the PC.
Bob