The recurring error, "Preparing Security Solutions" that has been surfacing on your systems is NOT a valid Windows 7 error. It is a message that is being generated by a virus that has been cleverly engineered to masquerade as a valid system program.
This virus has been so cleverly devised that normally effective anti-malware tools like MalwareBytes have not been useful in detecting/removing the problem.
PUT SYSTEM SWEEPER ON A USB STICK
System Sweeper,
https://connect.microsoft.com/systemsweeper, allows you to start an infected PC and perform an offline scan to identify and remove viruses, rootkits and other advanced malware. System Sweeper is a free standalone, bootable malware and virus remover from Microsoft.
NOTE: A fine tutorial on the System Sweeper is:
How to use the Microsoft Standalone System Sweeper
Download System Sweeper (about 576 kB):
https://connect.microsoft.com/systemsweeper
Insert 256 MB or larger USB stick into a usb port.
Run the downloaded program--mssstool64.exe or mssstool32.exe
Choose the option to install to USB.
Caution: The install program will format the usb stick.
The install program will download about 200 mB more.
After the install is finished, leave the stick in the usb slot.
Run the program you downloaded once again.
This 2nd run, and any subsequent runs, will download the very latest anti-virus definitions (about 60 mB).
To keep System Sweeper up-to-date, simply reinsert the usb stick and run the installation program, mssstool64.exe or mssstool32.exe, again.
The initial, full scan by System Sweeper can easily take several hours, but subsequent quick scans will be shorter.
Remember, your computer is being very thoroughly checked for all types of malware.
The results of System Sweeper will be in:
\Windows\Standalone System Sweeper\Support as one or more files with a LOG extension which can be viewed with Notepad.
