I have toshiba satellite c655-s5512,and I need these drivers please(network controller,PCI simple communications contorller and SM bus controller thanks.
The SM Bus will work properly in spite of the yellow mark in Device Manager that says it doesn't have a driver. The Simple Communications device refers to an old-fashioned MODEM for telephone calls and faxes or dial-up internet. If you don't need it, there's no need to worry about it.
For the network adapter, you need to go into Control Panel>System>Hardware>Device Manager and scroll to Network Adapters. The ethernet and wireless will be there so right click the first, go to Properties and then click the Details tab. Scroll to HardwareIDs and take a note of the four characters which follow VEN for Vendor and also the four following DEV for Device.
Go to http://www.pcidatabase.com and input those characters in the two relevant boxes and follow the trail to the right driver. When you find the list of the Vendor's drivers, they aren't in order so use your browser's Find facility to track the Device details. With luck you'll have an executable file but some will be a zipped folder.