Reinstall Avast ?

Hey guys, my buddy told me he had a Malware problem and I told him to come here at MG, but instead he took it to a so-called tech who ran Combofix.. Well, everything seems to be working fine, so far, but he said Combofix deleted Folder sysmachine.dll, and all the Avast set up files. He says it's all working good but he wants to know if he should uninstall and reinstall Avast or will it still work the same with the set up file deleted ?

 

Update on my friends situation. I told him he should have no problem, and he told me everything seems good.