I recommend you UnHackMe - Ultimate Malware Killer for fast malware removal:
Free DownloadFully Functional 30-day Trial. No credit card is required.
Reviews. EULA. Privacy Policy. Uninstall.
The file promp3_inst.exe is a very questionable.
We suggest you to remove promp3_inst.exe from your computer as soon as possible.
Promp3_inst.exe is Trojan/Backdoor.
Kill the process promp3_inst.exe and remove promp3_inst.exe from Windows startup.