Error 1324 during SEP 12 installation

Hi All

I have a problem during SEP 12 upgrade on a Windows 2008 Standard 32 bit server.

When I launch setup I have an error message
Error 1324. The path progam files contains an invalid charatcer

Already serched on Google, but there is solution about this error only for path to Documents and Images folder and the solution doesn't apply for my issue.

On Symantec forum suggest also to search Program Files on registry to find where the invalid character is, but is a endless search .........

Tried also with CleanWipe tools, it run successfully removed the prevoius version ( SEP 11 ) but doesn't solve the problem

Could you help me ? Have you any hint or suggestion ?

Thanks

Luca