BSOD random crashes

I have recently started getting random crashes and I don't know why. Here are the dump files. 112312-14929-01.dmp11/23/2012 8:27:47 AMKMODE_EXCEPTION_NOT_HANDLED0x0000001e00000000`0000000000000000`0000000000000000`0000000000000000`00000000ndis.sysndis.sys+58308 x64 C:\Windows\Minidump\112312-14929-01.dmp6157601303,433 112212-15958-01.dmp11/22/2012 8:08:43...