Vista - problem with external drive for backup

I have set up automatic backup in Vista to an external hard drive on USB2. I turn the power of to my PC equipment nightly through a Belkin surge master including the external drive. On powering up the external drive runs but my PC does not register it, PC boots ok. I have to turn the external drive off and on again for recognition on my PC, this prevents auto backp from working correctly. When external drive is turned on/off it works well. Any suggestions would be helpful.

Mine does the same. Why not just turn off the external HDD when you turn off the PC, and turn back on the external when you turn back on your computer?

Thanks that is what I am doing now but this defeats the object of auto backup

I autobackup, I just turn on my External before the backups commence. The other option is to put your system to "sleep" or "hibernate"-instead of turning it off, Or turn off the PC/External at the same time, and turn them both back on at the same time.