emachine no signal on, turn on shows no sig and goes straight to sleep. computer type emachine T3304 desk top pc AMD sempron 3300+, optic drive DVD/cd-rw, Hard drive 100gb ata, 256mb ddr sdram modem 56k, video nVIDIA Geforce 6100 pci express slot available. this originaly had windows xp. upgraded whole system to windows and windows 7 and down loaded free iobit security program. I noticed problem right after i was doing a security check i think either I or the security program had selected a driver for the monitor and deleted it. it started out turning on off intrmitenly then i shut down computer took apart put back to gether now just straight to no signal and then right to sleep. sounds to be runing fine just monitor signal bad. at the moment i have all cards , momry out ,etc..... as somone suggested in one of disscussions at this web site.i will fire it up in a few mins to see if she goes or blows cross fingers. (Also can somone please tell me the deffenitions to these VGA,dvi,Mobo,PCI,PSU,CPU.) it would be apreciated thank you

VGA- Visual Graphics Array
dvi- Digital Visual Interface
Mobo- Motherboard
PCI- Peripheral Component Interface
PSU - Power Supply Unit
CPU- Central Processing Unit