I managed to finally fix vista on my computer, and I managed to mess it up again. Something very strange happens on startup into vista. I get to the login screen, and log in successfully. Then, the screen goes blank. The first time I encountered this, there was a popup error message that said something like "Permissions for this feature have been blocked" or something like that. It doesn't show the popup messages anymore, but the truly odd thing is that I can still hit Ctrl+Alt+Del, and select the task manager. The task manager window appears, but still nothing else. It's like my desktop won't show, but the rest of the OS is working fine. I tried going into the boot disc to the command line, and running the chkdsk command, but it said the disk cannot be written to. What should I do to fix this problem?