to boot to safe mode or restore the computer to prior restore points, you can try any of the following method:

Method I:

Use a clean computer to download the following files in a flash/USB drive:

http://download.bleepingcomputer.com/grinler/rkill.com
http://download.bleepingcomputer.com/grinler/rkill.exe
http://download.bleepingcomputer.com/grinler/rkill.scr
http://download.bleepingcomputer.com/grinler/rkill.pdf
http://www.raktor.net/exeHelper/exeHelper.com
http://www.raktor.net/exeHelper/exeHelper.scr

Insert the flash/usb drive in the affected/infected computer.

Just let the rogue program do its thing without closing it, then execute 1 of the above files. You might need to try to execute it many times. The above files are the same but the purpose is to shutdown the processes of the rogue program.
If the rogue program was shutdown or has been closed by the above files, immediately open the installed scanner in your computer. Update it then run a quick scan.

You can also try to scan using the following:

Malwarebytes' Anti-Malware
http://download.cnet.com/Malwarebytes-Anti-Malware/3000-8022_4-10804572.html

SUPERAntiSpyware Portable Scanner - no install is required.
http://www.superantispyware.com/portablescanner.html

EmsiSoft MalAware - no install is required.
http://www.emsisoft.com/en/software/malaware/

Hitman Pro. This is trial for 30 days with removal feature.
http://www.hitmanpro.nl

Method 2:

Download any of the System Rescue tools using a clean computer:

VIPRE Rescue
http://live.sunbeltsoftware.com/
Avira AntiVir Rescue System
http://www.free-av.com/en/products/12/avira_antivir_rescue_system.html
Kaspersky Rescue Disk
http://support.kaspersky.com/faq/?qid=208282173
BitDefender Rescue CD
http://download.bitdefender.com/rescue_cd/
F-Secure Rescue CD
http://www.f-secure.com/en_EMEA/security/tools/rescue-cd/
Dr.Web LiveCD
http://www.freedrweb.com/livecd/

You need to burn the file in a blank disc and use to boot the computer. It will scan the computer before Windows logon which means the rogue program or any malware will be removed, if found by the scanner.