Windows 7 Home Premium 64-bit SP1 slow startup

Hey guys, I'm in a Computer Repair class, and I've been given a project that's a little over my head. A client came in and dropped off his Toshiba Satellite C855D laptop, saying the startup time is very slow. I timed the startup time at 7 minutes. The start up time break down is: from button push to welcome screen: 50 sec; from welcome screen to desktop: 6 min 6 sec.

I've done all I could think of doing, from disabling start up programs to running a check disk. I also ran an AVG whole computer scan, and a MalwareBytes scan with no results from either. The hard drive isn't fragmented at all, I ran Disk Defragmenter. I ran CCleaner so, as far as I can tell, nothing is bogging down the system and there's no registry errors. I just don't know what could be causing this problem.

Any help would be greatly appreciated, thanks in advance.

Is all its memory working and available to Windows? Right click on Computer, select Properties. The main screen will tell you how much is installed but will also tell you if some of it isn't available if that's the case.

Event Viewer may be able to pinpoint a slow bootup service. Or look into using Soluto which is rather good at identifying slow driver loading, services or startup progs.