Ok, but it doesn't state anywhere that you can flash an OTA on its own. Or that you flash an OTA via fastboot. My point being that trying things that aren't documented (and without knowledge of what you're doing) almost always lead to someone bricking their phone, and then that person realising after the fact that they shouldn't have been trying those things without proper knowledge. There are two ways to learn, one is slow and takes a lot of work, the other is very fast and expensive. I'm trying to save you from the latter.
Anyway, back to your main issue. You actually didn't state anywhere in your OP that you were running the RUU as an administrator, that's why I asked. Are you sure that the RUU fully downloaded correctly? Does the program even start up? Or are you greeted with errors as soon as you try to open it? What's the file size?
Sent from my Evita
As for the main issue, I'm apologize, you are correct. I didn't state that in my main post. It was in response to another user. I can't say I'm 100% sure because i haven't checked, but I have downloaded the same file from about 3 different locations on this forum and have tried each multiple times with the same results. The file name is "RUU_EVITA_UL_JB_45_S_Cingular_US_3.18.502.6_Radio _0.24p.32.09.06_10.130.32.34_release_signed_With_P artial.exe". The file size of all 3 of them are 79.4MB. Just for some extra information, I've also tried the 5.18 RUU exe file which is 621 MB file name is "HTC_One_X_RUU_5.18.502.1.exe." I have only downloaded that file from one source and only one time so I can't verify against another file size on that. Although that file returns the same error message as the others. Do you think I could have corrupted downloads?
And again I appreciate the help. I'm sorry if it seems I'm over-explaining things. I just want to give any possible information that could be relevant to the issue.