Convert a 2007 SharePoint template to 2010

The other day I had to migrate a few SharePoint 2007 lists to a 2010 site. However, when I tried to do so, I received a message stating that my templates were not supported. Luckily, I found a fix.

Hopefully, this can help others. 

1. Download the 2007 list template to a local folder
2. Rename the .STP to .CAB
3. Open the .CAB 
4. Extract the .CABs manifest.xml to a local folder
5. Open the xml in Notepad
6. Search for  ProductVersion. This it will be 3
7. Change it to 4
8. Save your change.
9. Now Repackage the manifest.xml into your .CAB
• This can be done by going to your Start menu and selecting Run
• Enter cmd
• Then entering the following Syntax: makecab.exe {folder}\manifest.xml {folder}\{template-name}.cab Example: makecab H:\myfolder\manifest.xml H:\myfolder\2007template.cab
10. If you donot receive a error message go back into the folder where the .CAB is saved.
11. Open the folder and review the manifest to make sure the Product version 4 has saved within the xml.
12. If correct, close the file and change the cabinet's extension from .CAB back to .STP
13. Upload it into your SharePoint 2010 list template library. 

Now it should work.

Source: http://tom-dw.blogspot.com/2010/06/importing-sharepoint-2007-list.html