Folks, Son has an Acer Aspire M3910, 6 months old, with Windows 7 Home Premium SP1 64 bit. Suddenly following a reboot a number of devices stopped working. Device Manager shows 11 items with a Code 37 error including DVD drive, monitor, LAN / WLAN card, 4 x core Intel i3 CPU's, audio controller, a couple of bus enumerators and a H57 Express Chipset LPC interface controller. Have searched through the forums and tried the following:- 1) Checking for viruses from normal and safe mode using Sophos, MalwareBytes, AdAware and a couple of others - nothing found. 2) Change the registry to remove Upper and Lower limits to adapter entries. 3) Replacing the NDIS.SYS file with one from a different machine. 4) Checking version and size of above, are correct. 5) Reinstalling drivers from the inbuilt eRecovery tool. 6) Downloading new drivers from the supplier and installing them. 7) Rolled back to previous restore point. 8) Tried sfc /scannow at command prompt - nothing found. All of the above have produced no difference whatsover. I really don't want to rebuild the machine if I can help it but I as running out of ideas. Would be grateful for any others. Many thanks, Stu ...