Patch updates can be upgraded simply by downloading and installing the new version. Upgrading a USoft application to any other major version involves a sequential upgrade of the repository, for example going from 8.0 to 10.0:
 

•          USoft 9.0        :           8.0 -> 9.0                                Upgrading to USoft 9

•          USoft 9.1        :           8.0 -> 9.0 -> 9.1                      Upgrading to USoft 9.1

•          USoft 10         :           8.0 -> 9.0 -> 9.1 -> 10         

and 

The upgrade process itself is equivalent along all versions, so you can upgrade your existing application using the same process of using the upgrade tool. We recommend going through the upgrade guidelines before and after upgrading about which more information is found in the above links.

Notes:
USoft 9 uses .NET Framework 4.5, where USoft 8 uses .NET Framework 3.5

NET 4.5 is available starting from Windows Server 2008.

Regarding license server software:

• • Usoft 8 uses FlexLM v8.2
  • USoft 9 uses FlexLM v11.10 and FlexLM v11.15
  • USoft 9.1 works with FlexLM v11.15
  • To obtain the license server software, please contact us via support@usoft.com