Broken .net app due to server configuration?(repost)

I went into the server control panel and changed a username for FTP/Microsoft FrontPage Login. After that I got a 503 error and had to reboot, then certain functions of my .net site quit working. It is pulling data from the database ok, but when I click certain buttons I receive "An error has occurred." (see the attached server error) I changed the username back but it still acts the same. Something may be tied to that username and maybe it is a common asp.net practice, but I don't know what it might be. It is more likely that the developer set things directly in IIS, instead of using Plesk like they should have. When the computer rebooted, Plesk changed something. It seems like the program can't find certain things. I already know for sure that they changed there are two folders containing the site www and httpdocs. But it is not as simple as moving the files, because we tried that. The original developer is not available to help with this. I have RDC and Plesk CP access to the server. I am available on msn messenger and also have Team Viewer so we can look at the settings together. You can bid for the project, or per hour. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform Windows server 2008. asp.net , Plesk 9