help

i recently got my pc infected by downloading some files.well basically on startup i got multiple dep errors and mainly for explorer.exe .which i seem to have resolved using the various programs mentioned in the read me first..but i still have a feeling my computer is infected,many items still give me encountered an error messages.. ..the scans detected and removed eveything but combofix still says its infected..oh and id like to know why everyone says that you should disable system restore when scanning or anything when combofix enables it if its disabled..