PCI serial port driver error on Dell E6400 Laptop with Win7 entprz64  

Hi DBerming,

Regret any inconvenience.

'PCI serial port driver error' points at a Chipset driver. Please share if any part (Motherboard, Hard Drive, etc) was replaced on the notebook recently. Or did you make any software change (Windows re-installation, etc.) in the unit? Would also like to know if you've tried updating Windows, as suggested by 'maxie'.

If you're still facing this trouble, you may try the following steps:

1. Update Chipset drivers, using the following links (Note - Links given below are tested to work with Latitude E6400 notebook with Windows 7 64 bit):
Click http://dell.to/138LEgl to download 'Intel AMT HECI' driver
Click http://dell.to/13l9qaL to download 'Intel AMT SOL/ LMS' driver

Follow through with the installation as per the on-screen instructions. Allow the system to restart and share results.

2. If the issue still persists, try flashing system BIOS. Note: Before flashing the BIOS please check the following: Battery should have 10% or greater charge; Adapter should be connected; No external devices should be connected; All other programs should be closed and documents saved

Click http://dell.to/16JS8c2 to download/install the latest BIOS version. A33 version was recently released (29/04/2013) and has an update for the 'Intel(R) Active Management Technology firmware'. Apply this update and share the findings. I'll take it forward from there (If not done already).