HOWTO: PPTP: Ubuntu Client connect to Windows VPN Server

The company I work for just starting to use Windows ISA Server (or whatever) in some places.
And also, they use the Windows server to be a VPN server.
As Micro$oft doesn't officially support OpenVPN, and we don't consider IPsec to be used for end users, they decide to use the fu*king insecure PPTP, which I would definitely never wanna try.
That's where my Nightmare starts.

After some tries, I can use the VPN on my Android phones, and it seems works fine on iPhone, too.
But I just can't get it work on my Ubuntu boxes. The VPN connection just cannot established and I got error in my /var/log/syslog like this:

Mar 17 00:03:13 0xB1uE7 pppd[17577]: EAP: peer reports authentication failure

No matter what, I got it work in the end, finally.
And these are the steps how to get it work.

1. $ apt-get install network-manager-pptp
2. $ sudo /etc/init.d/network-manager restart
3. Click the NetworkManager Applet
4. [VPN Connection] -> [Configure VPN] -> [VPN] -> [Add]
5. Choose [Point-to-Point Tunneling Protocol (PPTP)] -> [Create]
6. Fill out those neccessary informations and click [Advanced]
7. In {{Authentication}} section, CANCEL [PAP], [CHAP], and [EAP], KEEP ONLY [MSCHAP] and [MSCHAPv2] SELECTED.
8. In {{Security and Compression}} section, SELECT [Use Point-to-Point encryption (MPPE)], and choose {{Security}} to be [All Available (Default)]
9. [OK] -> [Accept] -> [Close]
10. Now click the NetworkManager Applet
11. Click [VPN Connection] and click the profile you just created.
12. Wait for few seconds till it get connected.
13. Done.

Hope this HOWTO can save a tree and a kitten.