Might be a nic driver
, or power setting.
Check device manager (type device manager in search) see if your network devices are listed and dont have ayellew triangles. also see if you have any unknown devices
event viewer type event in search and go to windows log>application tab. Look for errors relating to the problem
If you have been getting true blu screens go to c:\windows\minidump, zip the dump file (*.dmp) and upload it to us.
If you need any help let us know