When I switch on starts up fine then the boot manager screen comes up with erroe message : windows has encountered a problem communicating with a device connected to your computer.

carolann, May 2014

Restoring to a previous state may not work if there is a faulty device.

Despite the error, does the boot process complete?
If it don't complete, at what step does it fails?
Try disconnecting all USB devices and any other external component. One of them may be faulty.
Reboot.
If the computer boot correctly, then one of the USB, or other, devices is faulty. Reconnect one and check if it works correctly.
Reboot.
Repeat untill you find the one that don't work correctly and prevent your computer from booting normaly.

You may have a broken driver.
Reinstall the main drivers: Video driver and sound drivers. You may also check for the motherboard drivers.

Electro, June 2014

try (systems restore) putting it back to in time to a date when its was working as normal. look systems restore,, for the windows that you have , xp /vista, windows 7 .. ect.

j, May 2014