How to fix wrong Created, Modified, Accessed dates on files/folders?

Cleaning up the friend of a friend's completely virus infested, badly working computer.

Windows 7x64 HP Pavilion g6 Notebook PC

The Basics:

While I was beginning to install and manually offline-update various anti-malware tools so that I could begin to determine what I needed to do to get this thing clean and properly operable, I noticed while looking at Programs and Features that many of the install dates for various software were dated in various months in 2013. My installations were 1 year, 2 days ahead of the current date. Windows Explorer shows this to be consistent throughout the files and folders installed.

Looking at the install dates for some of the HP proprietary software/bloatware, I can tell this behavior started some point after the computer was purchased and used (the bloatware installation date was one day after the warranty start date listed in the BIOS). I am presuming dates on files and folders created, modified, or accessed from the point of the initial occurrence of what caused these particular incorrect future timestamps are the only ones affected.

The clock and date were wrong by the exact amount forward as were the install dates for the files I installed, so, as expected, the files were taking their timestamp from the computer's time. I assume whenever the computer date and time were maladjusted is when the problem started.

I fixed the time and date, but the files and folders did not adjust their timestamps, again as expected.

So, here are my questions:

1. Are there any particular problems I am not considering which could be caused by the incorrect dates, other than some particular searching and arrangement issues, which in this case I think would be superficial? This type of date information is just descriptive metadata for files and folders, correct?

2. Is there any way to fix this? I cannot think of any, but maybe there is something I am missing, hashing it out in my mind. If the BIOS clock and the Windows date and time settings were separate and the date metadata were generated based on a timer referencing the BIOS clock, then I could see a way to repair this. But, at least on this notebook, a change in one is reflected in the other--I think this is how Windows OSes operate in general. Anyway, any ideas?

3. Finally, after I finish cleaning and repairing the notebook, is there any way to globally reset all of the date metadata on all files/folders to reflect the present? So long as having incorrect future timestamps does not affect operation, then this is superficial, but it is irrationally driving me crazy. If it were my computer, I could not stand it--barely can stand it as it is. I have found a program that lets you reset all of the dates of all files in a folder, or the dates of all folders visible when opening a directory or subdirectory, but not both simultaneously, and so of course not anything that would change the dates of all the files and folders nested within one another from root.

Going to go snag myself some feta and olives from the grocery store and hopefully one of you will explain why my solution is so obviously obvious. If not, I will likely have this computer for a day or so, so I have a bit of time for your individual or collective genius to shine through.

I know I am not supposed to bump this thread, and I will not do so again if it falls off the first few pages again without a reply, but I only have this notebook for about 24 more hours, so, in hopes that someone who hasn't yet looked at it might see it and have some insight, I am moving it back up. And I am assuming doing this is better than simply opening a new thread rewording the same exact issue.

If no one replies, I won't move it up again. Any help would be appreciated.

If the moderators have absolutely no flexibility for this, then please lock the thread, with my apologies.