In most cases the image wont go bad.But if a virus damages your files then you are in bad luck.Now watch this...to me it was even worse.Many many months ago I made an image file of my entire HDD which is whole C: partition.After the image was finished,few weeks later,the damn NTLDR disappeared.I could fix that easily,but I decided to rather return my image file back so I can see how it works and after the process of returning the image file was finished,Windows did not boot.It showed BUNCH of missing files.First it was HAL.DLL.I repaired that,then it was NTDETECT.COM.I repaired that too.Then it were few DLL files and in the end it was NTLDR lol.I repaired that too,but then AGAIN I had the NTLDR error.No matter how I repair that file,it simply says it's not there.The reason was because somewhere in the Windows registry it was written like NTLDR is not there,when it actually is.Since that moment I was SURE that the image file was bad.Now watch this.A week later I made a test and made the image file again on the SAME WAY as the last time,I returned that image file back and it worked like charm.LoL!!!
So yeah it can happen.It happens in 1% cases and I guess I was that 1% that day.Thank God I had my HDD cloned with Linux Ubuntu so I didn't lose anything.

Damn I hate when these things happen to me lol xD It drives me crazy AAAAAAAA xD xD xD!!!!!!