To Find ID used to a installer entry

convert_guid_to_hashed.py

#!python

# This is a script to calculate ID used in HKLM\Software\Classes\Installer\Products 
# from the GUID of the product as mentioned in uninstall entry in registry.
# Explaination: http://superuser.com/questions/570598/how-to-force-uninstall-a-software-that-is-installed-by-msi-package/570620#570620
import sys 
from _winreg import *

def reverse_alternate(s):
	if len(s)%2 != 0:
		print "Error in input for alternating reverse."
		return s
	x = ""
	i = 0
	while(i < len(s)):
		x += s[i:i+2][::-1]
		i += 2
	return x

guid = sys.argv[1]

broken_guid = guid.strip().split('-')
	
output = broken_guid[0][::-1] + broken_guid[1][::-1] + broken_guid[2][::-1] + reverse_alternate(broken_guid[3]) + reverse_alternate(broken_guid[4])

print output