From what I understand, the actual file structure in c: \ windows \ Microsoft.Net \ Framework has folders with .Net versions. On my computer, I have folders up to v3.5, or with:. \ Windows \ Microsoft.Net \ Framework \ v3.5
There are many problems with this, including security issues.
The second, and probably best answer is to check your Windows registry.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework\NDP
, .
: stackoverflow java.
/ Windows Java
http://www.trustice.com/java/jnireg/ .