File Size and Date Differences on different machines

[kpassaur]

My goal is to confirm a certain file exists (PDF) and that it has not been altered. It has to do it within reason in other words if someone was really smart they could get around it and I understand that. My thought was to confirm file size or creation time.

First I check to see if it exists and it does.

Second I check the file size, on one machine (Vista) it returns 20104 but on XP the return value is 20126

So, this method does not work, I can only think of the operating system is causing this as it is the same file, same ver of MS.

So, I decided to confirm it with File time. This seems reasonable as I am not using a date but I am doing it by seconds "HHMMSS".

The time on Vista is 053116 and on XP 052932

So, this method did not work. Any ideas as to what causes this?

[kpassaur]

I think I have it figured out. So please disregard this.