Let's get through a short bit of background first.
My school requires Symantec Endpoint Protection to be installed on any Windows-based computer on the network. I deal with this while living on campus but I remove it every summer. In order to uninstall the normal way through Programs and Features, a password is required which the school refuses to give me until I graduate or transfer. So I remove it manually following instructions given on the Symantec website, here. I have done this successfully on a Vista machine but got all sorts of problems with my current machine running Windows 7.
Upon removal I lost the ability to connect to any networks either wireless or wired and none of the fixes I found had worked. So I did a system restore to a point prior to the manual uninstallation and now every time I login it takes about 5 times as long and then presents a blank white screen for a minute or so. The icons in the start menu also take longer to show up. The problems occurs both in safe mode and normal, although it is a black screen in safe mode.
At first I thought it may have something to do with my BIOS or video driver so I updated those and the problem persists. I also disabled all start-up programs and that did not solve the issue either. All virus and malware scans turn out clean and I have run out of ideas. Any help or guidance is greatly appreciated.