Laptop got infected by gphone.exe?

Hello there and I need help, yesterday morning my laptop was running fine until my father plugged in his cellphone into my laptop. Then it started to freeze so I had to restart after that windows theme won't load it seems the explorer.exe is corrupted and I can't access task manager or anything. I can only access the internet and task manager on a guest account. Please help me with this I can't afford to reformat because I have an installed program that I really need and I can't download it on the internet.