ROM Restore?

[Guest _Dell_]

Hy,

I would like to know if I install a diferent ROM and I modify my phones SPL, and during setup something would go rong, for example the process would stop, after restarting my phone if I have no backup of my old Rom, can I simply connect via USB to PC and run the UK ROM for example?Or witouth an image I have no chance to install or restore eny other Rom using USB connection to my PC?So the Rom image (on miniSD) is the only way to restore?Thanks...