Windows 7: I am an idiot maybe

I bought a PC (my first) and it was equipped with Windows 7 Ultimate. I did'nt get a disk with it and was told that was normal when buying from someone who builds systems. Now it seems that my OS is a pirated version and was possibly disabled by Microsoft. I am not to sure what happened so I came here to see if anyone has any ideas. I went to resart the PC and the options were start normally or StartupRepair, I tried to start normally but it froze and restarted again with the same options. I tried the startup reapir a few times and it will not fix. I am not very computer friendly and it almost seems to me that my only option is to buy Windows 7 and reinstall it and lose my hard drives contents. If anyone has any suggestions otherwise please please tell me.

ProblemEventName: StartupRepairOffline
ProblemSignature01: 6.1.7600.16385
ProblemSignature02: 6.1.7600.16385
ProblemSignature03: Unknown
ProblemSignature04: 21200940
ProblemSignature05: AutoFailover
ProblemSignature06: 16
ProblemSignature07: CorruptAcl

OS version: 6.1.7600.2.0.0.256.1
LocaleId: 1033
SystemRestoreError: 0x80070057

I would take it right back where you got it and demand your money back or have them install an operating system.

The person I bought it from is long gone with no forwarding address, that was my first stop. And as far as it not being genuine I was told by a friend when he saw a remove wat folder. I should have done something then but I am not a rich girl and a legit Windows 7 is around $ 300. I suppose thats a moot point now however.

How long ago was this purchase and was it done online or local? Have you tried the steps that were psted yet?

Also, you can verify if your Windows 7 copy is legit or not with with Activation Tool.

Welcome
I see no reason for me to continue the guessing game to figure out if your OS is valid or not. I can say that at the point that you realize that it probably is and you want to try and save your stuff, this may be an option. At least give it a try.
Use Ubuntu Live CD to Backup Files from Your Dead Windows Computer - How-To Geek

Work though these steps for Troubleshooting Windows 7 Failure to Boot - Windows 7 Forums

You can buy a retail OEM version for around $100 to replace the one which is non-Genuine since it was a builder's installation.

However first I would get it running, then try reinstalling the Product Key at Control Panel>System Change Key link. If it is cracked then it will fail.

Any time you buy preinstalled Windows, it should have a COA sticker on the machine to prove it is genuine.

If no sticker is on machine you can audit the installed key using Belarc Advisor - Free software downloads and software reviews - CNET Download.com

I am 100% sure that it is a pirated version. I was told that Microsoft firebricks the PC when they find a pirated version so I am guessing that is what happened here. I have been doing all the updates since I bought it and had no problems before. As I said earlier I am a 1st time buyer, I thought I was getting a good PC with a genuine OS. I would guess that recovering my stuff and starting over with a genuine OS is my only option.

I heard that you lose features slowly and get a warning, until its gone.

Before doing anything be 100% certain, give them a call
Microsoft Volume Licensing - Activation Centers

I do appreciate all the help, I am totally out of my depth here. Maybe I should take my PC to a reputable dealer and have a genuine OS installed ? But will it wipe out all that I have or is it like an overlay ? Sorry if my questions seem basic but I am REALLY without a clue with this type of endeavor.