Use GetSystemMetrics( SM_CLEANBOOT ), here are some inline functions, you can understand what they do from their names…
__inline BOOL IsNormalBoot()
{
return ::GetSystemMetrics(SM_CLEANBOOT) == 0;
}
__inline BOOL IsSafeMode()
{
return ::GetSystemMetrics(SM_CLEANBOOT) == 1;
}
__inline BOOL IsSafeModeWithNetworkBoot()
{
return ::GetSystemMetrics(SM_CLEANBOOT) == 2;
}
Well I’m not talking about the one that your cat runs after but the one on which your palm rests. 
It’s quite easy, use GetSystemMetrics and associated mouse indexes. I’ll show demos here…
// Use GetSystemMetrics ::GetSystemMetrics( SM_MOUSEPRESENT );
// Use GetSystemMetrics // There is one more index present called SM_MOUSEHORIZONTALWHEELPRESENT, check out and tell me! ::GetSystemMetrics( SM_MOUSEWHEELPRESENT );
// Use GetSystemMetrics // You can also use this method to test presence of a mouse ::GetSystemMetrics( SM_CMOUSEBUTTONS );
Quite handy right? Most windows developers knows these but hey just in case you missed out.
Use any of these, but read the docs carefully before using them as they have some conditions associated with them…
IsNetworkAlive IsDestinationReachable RasEnumConnections InternetGetConnectedState InternetCheckConnection GetSystemMetrics( SM_NETWORK ) //(Try this one, if your find issues tell me, I'm curious)
First one is the best so far if you have IE5 and later.
