Well sometimes this happens to Some AutoCad keys. Here is how to solve this problem:
Download the official trial of AutoCad 2011 from Autodesk.
Begin the installation of AutoCad 2011 from the official Trial that you have downloaded.
Select I have my product information
Use the following serial number regardless of what is your purchased serial:
400-45454545
Use the product key that you purchased.
Enter the serial number and product key as shown in the photo
Begin Installation
Yes for default
Finish the installation and close autodesk
Restart Autodesk Product
Before clicking on Activate
Disconnect from the internet (This is very important because if you don't, Autodesk will get a report that you are trying to cheat them - even if you are not- and ban your original key)
Click on activate,will tell you bad number, close and click on activate again
Pick "I have an activation code from Autodesk"
This will give you a request code, copy this code. You will need this to get
your activation code
Example (non-working code):
qgcz z512 jq4d joy6 q95q 4r99 doky gezy
Open the Autodesk Activation Tool. (if you do not have it, ask your seller to provide you with it)
Click on Mem Patch (you should see successfully patched)
Paste the request code (that you copied before) in the corresponding field and click generate.
This will give you a group of numbers and digits, 56 in all
Example(non-working code):
A1B2C3D4E5F6G7H8I9J1K2L3M4N5O6P7Q8R9S1T2U3V4W5X6Y7Z1A2B3
Copy the activation code and paste it in the corresponding field on the installation program
Hit "Next" and you should see "License Active".
Hit "Finish" and you are done :)
Run the Activation tool as administrator and with UAC off in Vista or Windows7
Help, to copy (ctrl+c) to paste (ctrl+v)
