I just did a full scan on customers computer,when it finished it gave me a list of files it said it could't scan,i have never had this happen anybody can tell me what a'm i sopose to do?I'm running Malwarebytes right now to see what it says

first try running it in safe mode, could be stuff hidden from the os, run rootkit revealer see what it finds

Ok I'm running safe mode scan now now I ran malwarebytes and it didn't give me that message,but now I'm scanning with avast again.Plus I will run rootkit revealer another proplem I'm having with this E machine is when i plug my external hard drive in it don't bring it up on this computer,now on the external drive itself the green light flashes but the computer is not reconising it I plug in usb mouse and keybord they work fine I was wrong the keyboard does not work only the mouse

There is malware that will prevent a PC from recognizing an external drive connected to a USB port. I've had a few of them recently on customer's machines. If you can start in Safe Mode with Networking and use rkill first, TDSSKiller, rootkit revealer, and then Malware bytes, you might get USB useage back. I noticed you said the keyboard doesn't work (I presume the same machine...use punctuation please) then it may be a USB/hardware issue. Try a different keyboard. Since the PC has AVAST on it, have you used its boot-time scan?

I'm using boot time scan now the regual keybord works fine ps2 its just usb ports that are not funtioning.When I recived this the owner had done a windows restore to factory but he put in the wrong activation code,as soon as i started the computer it said windows needs to be activated I found the right key enterd it and did all updates.Windows Xp Home If all else fails I will do a re instal windows.Now that brings up another questain since this computer has a recovery concle instald f11 could it be currupt? would i be better of running windows xp disk?

Check in the device manager and make sure there aren't any devices showing a problem (needing drivers.)