PCI bus driver crash error

My Dell Inspiron recently visited customer service centre in Bangalore, India. After 1 month of usage when I visited My Dell>Check Up>Blue Screen Troubleshooter, it shows several errors regarding
The "PCI bus" appears to have caused a system crash. Every error are within 2-3 days interval.
I am running windows 8.1 with all drivers updated.
My USB slots are sometimes not working seems loose to me, and DVD drive also loses contact.
Also when I close the lid on battery (I have sleep setting), laptop generally never wakes back. Its running but the hard disk light never blinks. After a hard shutdown, everything comes back to normal.