Right now neither SAV or SEP is officially supported on WIn 7. SEP does work on Win7 but its not supported.

Norton AntiVirus 2009, Norton Internet Security 2009 and Norton 360 Version 3.0 only these these support WIn 7

http://www.symantec.com/norton/theme.jsp?themeid=w...

http://www.microsoft.com/windows/antivirus-partner...

Check these links  for additional details.

You can install SEP 11.0 MR4 MP2, it works on Win 7, but Symantec will not support it if you run it on Win 7. SEP 11.0 RU 5 is in pre-beta release which will support Win 7. If you participate Symantec pre-beta testing program, you can download it from Symantec site. 

 SEP 11 MR4 will work and also you can try SAV 10.1 corporate edition for windows vista, but you will not get support from symantec as it has stopped giving support with version 10.1. You can very well go for SEP 11 MR4, as i am also using the prduct and also Windows 7, i have been using it from the beta release of windows 7 and now going through with the RC one, still now i didnt face any problem with my A/V product (SEP 11 MR4). Cheers symantec team.....

I guess SEP 11.0 MR4 will work but not sure about wether u will get the support from symantec or not.
Ajit

After I install SEP 11.0 MR4 MP2 windows7 will crash and restore it OS to the last restore point without SEP.

Which build are you using of Windows 7? I'm testing on the RC build, post 7100, and MR4 MP2 works great with no issues at all.