Error installing and running pywin32 2.7

I am coming up with a couple errors after installing:

pywin32-217.win32-py2.7

I have recently upgraded ArcGIS to 10.1 and it uses Python 2.7 (as opposed to 2.6 that came with ArcGIS 10.0)

When I run the installer on a Windows 7 64 bit, it installs, but throws the following message:

close failed in file object destructor:

sys.excepthook is missing

lost sys.stderr

I had a simple python script to print to a printer from a folder containing .pdf files which worked before my upgrade

import arcpy, glob, win32api, os

pdfLoc = arcpy.GetParameterAsText(0)

try:
    copies = int(arcpy.GetParameter(1))
except:
    copies = 1

for pdfname in glob.glob(os.path.join(pdfLoc, "*.pdf")):
    fullpath = os.path.join(pdfLoc, pdfname)
    for copy in range(copies):
        win32api.ShellExecute(0, "print", pdfname, None, ".", 0)

del fullpath
del pdfname
del pdfLoc

Now when I run the script, I get the following error:

Traceback (most recent call last): File "Z:\ESRI\Python\Solstice_Tools_Scripts\Printer_Tools\Batch_Print_From_PDF_Only\BatchprintFromPDFOnly_Test.py", line 34, in win32api.ShellExecute(0, "print", pdfname, None, ".", 0) error: (31, 'ShellExecute', 'A device attached to the system is not functioning.')

Failed to execute (BatchPrintFromPDFOnly2).

I've been googling around and have tried a few solutions, like running the executable in troubleshooting mode, but the error persists. Can anyone suggest what may cause this?

As a side note, I upgraded 4 computers in my company to the new version of python and ArcGIS, and only one of them is throwing this error. The rest work fine.

Thanks, Mike