Cubase 4 and Windows 7 64 bit 3rd party compatibility issue

I’m using Cubase 4 and i just shifted to Windows 7 64 bit. I realised that 80% of all the 3rd party plugins that i was using fine on Windows Vista 32 bit, stop working on Windows 7.

I even tried to install them to the 32 bit directory and 64 bit seperately and still it doesn’t work. Some work and some dont, even the 64 bit ones installed in the 64 directory. and im quite baffled here as to how to go about it.
Any help would be appreciated. When i goto the plugin information to update the folders it gives me the following message ’ Cannot access low-level drivers '. It’s funny coz for example something like Sylenth and Punch don’t work , whereas some small free plugins work!

Im using Cubase 4 64 bit
Hp Omni i3 processor


Cubase 4 is not compatible with Windows 7!