The device manager will not show the problem that we are looking for in safe made as it only loads the minimum drivers to get to that stage.
I think that the first thing that we should try is to do a System Restore to an earlier date.
We can do this in safe mode so restart the pc and follow these instructions :
How to Start and Use System Restore
To start System Restore, follow these steps:
Click Start, point to Programs, point to Accessories, point to System Tools, and then click System Restore.
The first time you use System Restore, there are two options on the Welcome page:
Restore my computer to an earlier time
Create a restore point
Click Restore my computer to an earlier time and click Next.
A calendar appears.
In the calendar, choose which Restore Point to roll your system back to.
Click Next.
You are prompted to close all applications before completing the Restore process because the computer will restart.
Upon completion of the restart, a confirmation screen appears. Click OK to continue using your computer.
The next time you start System Restore, you will see a third option, Undo my last restoration. This is available in the event that the Restore Point you rolled back to does not correct the original problem that you were having and so you can easily get back to the point in time that you started troubleshooting.
If you havent installed any programs or uninstalled any recently you may have to "go back" quite a while but the system restore should only undo the OS alterations and not any data that you have saved on your pc.
If you are unsure about anything get back to me as I will be around for an hour or so yet