Fix Connection to Database issue - Sage Construct

I have a client who has an issue with Sage Construct. Sage Support has said they cannot help him with this issue as it is a network issue so he has called me in. The issue is that the program cannot access the Database which is stored on the local machine & the machine was running SQL Server 2005 the error was caused by an upgrade to Win 7 & in the process he changed the PC Name. The program was looking for the Database using the old PC name path.

I though this would be a simple change or edit somewhere but the guy had tore his PC apart trying to fix the issue himself. When i got there there was many errors so i uninstalled the whole program Sage Construct & SQL Server 2005.

When i attempt to reinstall from the disk it wants to install SQL 2008 rather than 2005  & it wants to use MSDE instead of ACT but aslo says that the MSDE\Setup.exe cannot be found on the disk.

I have installed without the MSDE but it states that there is a problem with an MSI file & Configuration of the Program Sage Construct cannot continue.

I have the old database file backed up but no program backup file as this guy did not complete a full backup of the program. Usually sage products which i have used have a built in backup util.

could anyone help please i was hoping that i reinstall the program switch the database files over and everything would fall back into place but so much has changed from the initial install i am not confident.