You will need to enter both the serial number and the product key for the suite on the ‘User and Product Information' page of the install wizard. As you cannot change this after the install you will need to uninstall and reinstall. The product key for Autodesk 3ds Max Entertainment Creation Suite 2011 is 661C1. Double check the serial number and product key values in the email you received or on Subscription Center so you don't have to reinstall again.
Your best bet is to get the serial number and product key information then go from there which might require a reinstall and cleaning out some folders. Are you using the installer for the suite or individual product installers? The suite installer should be used and should not produce this .pit error.
Subscription customers who are in the role of Software Coordinator will have received an email. The email, which is sent from Download@autodesksubscription.com, contains the customer's serial number and the product key, which is needed for installation. Please check junk/spam folders because the emails sometimes end up there.
Customers who have misplaced their notification email can access their serial number and product key directly from the Subscription Center:
1. Go to Contract Administration
2. Then click on Coverage Report
3. Then, under the Contracts section, click on your contract number.
4. Products are listed in the Products section with serial numbers and product keys.
Customers who are experiencing problems with their Subscription upgrade can contact the Business Center at firstname.lastname@example.org.
The error for the .pit file can be resolved by deleting the ProductInformation.pit file found on the workstation in the following locations:
C:\Documents and settings\All Users\Application Data\Autodesk\ADLM\ProductInformation.pit
Windows Vista, Windows 7:
Douglas Lauritsen, Autodesk Product Support
Access a broad range of knowledge to help get the most out of your products and services.