the windows security center service can't be started

Excellent.

Looking at the system specs, I would suggest 4 GB ram instead of the 2 GB. You will get a performance increase and run into less problems.

Let me know when the full scan by the Microsoft Standalone System Sweeper finishes.

Read the following very carefully.

Follow the procedure given.

When the FULL SCAN by the Microsoft Standalone System Sweeper is finished, then
attach the log files to your next post.

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.

Safety Scanner, Microsoft Safety Scanner - Antivirus | Remove Spyware, Malware, Viruses Free, is free, downloadable, provides on-demand scanning and helps remove viruses, spyware, and other malicious software. It works with your existing antivirus software.

If the target computer has a working internet connection, then you may prefer to use the Safety Scanner.


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.