SH3-SH4 and W7
 

How is the installation of this games on W7.Do they work ok?

Works just fine on Windows 7 as long as you do not install into the default location in Program Files (x86). Instead, make a separate folder and call it Games, or Silent Hunter, or whatever you like and install the game there.

That's strange. I had it on Win7 on a default folder and it never gave me any trouble.

It'll work in the default location absolutely fine if you disable UAC, obviously for computer novices and those that think clicking on a flashy link offering free something-or-other is a good thing then this isn't recommended, but if you're quite conscious of the sites you visit and have robust and efficient antivirus/malware programs then it's not really an issue - and makes normal life with a PC livable rather than answerable.

Also check your graphics card. I'm running a simple E-Machines with W7 and Nvidia Gforce 6150SE, but when I tried to update my drivers to nforce 430 the periscope and bridge fuzzed out to where you couldn't make out anything. After uninstalling the nforce 430 update it worked fine again. So far its only the 6150SE nforce 430 driver that I know of that does it.