It's a ransomware infection.
As your Safe Mode options are disabled...
Try this:
Use a working computer to download the trial version of HitmanPro. You then run the program, but instead of using it to scan, you use the Kickstart feature to burn HitmanPro to a flash drive. You then boot your infected computer to the flash drive and scan.
This link takes you to the HitmanPro download:
http://www.surfright.nl/en
This video shows the creation and use of the Kickstart flash drive:
http://www.youtube.com/watch?v=RW3PG0YDy3Y
If you have no luck with that...
There is at least one example of ransomware that encrypts files beyond recovery (nothing can decrypt them...which raises the importance of making regular backups). West Yorkshire Police ransomware encrypts, but can be decrypted...see below.
There are simpler fixes for SOME of the ransomware infections, but this should work with all forms of ransomware...even those that disable every Safe Mode option, plus Regedit and Task Manager, etc....
Use a working computer to download and burn the Kaspersky Rescue Disk 10 .ISO file. Burn the file to a CD or DVD or flash drive, then use it to boot your infected computer. Once at the desktop, use the WindowsUnlocker feature.
This link is for the download of Kaspersky Rescue Disk 10. It's primarily designed to boot and disinfect computers that have been rendered unbootable due to an infection, but it's fine to use it on an uninfected machine. The .ISO file is 262MB in size, and it's easier to burn it to a CD or DVD than a flash drive, but the link does includes instructions on how to burn the file to a flash drive (USB device):
http://support.kaspersky.com/viruses/rescuedisk
If you don't have burning software installed on the working computer, download and install Ashampoo Burning Studio 6. It's free, and I recommend it...I use it myself:
https://www.ashampoo.com/uk/gbp/pin/0710/0-Offline/Ashampoo-Burning-Studio-6
Start up Ashampoo and select Create/Burn Disc Images...then select Burn a CD/DVD/Blu-ray Disc from a Disc Image.
Burn the CD or DVD, and use it to boot your faulty computer. You may need to enter your BIOS (Setup), and change the boot sequence to boot from CD first, but this isn't always necessary.
As already stated...when the CD or DVD or flash drive has reached a desktop, select the WindowsUnlocker feature. Once your computer is unlocked, you can either update tha virus definitions for the rescue disk and use it to scan your computer, or scan using your currently installed security product, or download a free product to perform a scan.
It should be noted that although certain ransomware pretends to encrypt some files, at least one example (West Yorkshire Police) actually does encrypt some files. In this case, you should use a decryptor utility supplied by Kaspersky Lab.
This video shows how to remove the West Yorkshire Police ransomware:
http://www.youtube.com/watch?v=1gwMhaJHwro
This link leads to the RannohDecryptor utility, from Kaspersky Lab:
http://support.kaspersky.com/faq/?qid=208286527
This WindowsUnlocker explanation and video link should also prove useful:
http://support.kaspersky.com/faq/?qid=208285998
http://www.youtube.com/watch?v=C5hvSlrOUlE
Hope this helps.