Second hand purchase of Office 2007 Home and student - What possible problems am I going to encounter?

Home and Student isn't limited to 3 "installations", it allows up to 3 active installations at the same time. In order for them to have legitimately sold it to you, they are supposed to uninstall all of their installations using that Product key.

In other words, you are allowed to run it on 3 machines a the same time. And to later transfer those installations to new computers if you wish

Worst case? It is infected with malware.  Other than that, it may still be installed on 3 machines so you couldn't use it.

If it looks like a real disk you may have lucked out and got a real bargoon <sic>. Here are some  links on how to recognize bootleg copies:

How to avoid Buying Bootleg copies online - http://www.eweek.com/c/a/Security/10-Holiday-Shopping-Tips-to-Avoid-Buying-Pirated-Software-351045/?kc=EWWHNEMNL12142011STR6

Microsoft Office 2010 Product Key and license Photo– How to find them? -http://techblissonline.com/microsoft-office-2010-product-key-and-license/

When you install or reinstall a Microsoft Office 2010 suite, you are prompted to type or to paste the 25-character product key. The product key is used during the Microsoft software installation to unlock the Microsoft Office suite. If you do not enter the product key when you are prompted, the suite may be locked. In a locked state, the functionality of the applications will be limited.

How to Tell if it Windows7/Office 2010 you bought is Authentic in pictures -http://www.microsoft.com/howtotell/

fake - What is a Windows Certificate of Authenticity (COA)? - How to Tell What Win and Office COA look like PHOTO- http://www.microsoft.com/howtotell/content.aspx?pg=coa&displaylang=en

2007 Microsoft Office Suites License Designations - 2007 Product key images -https://office.microsoft.com/en-us/products/2007-microsoft-office-suites-license-designations-HA101819164.aspx

Office 2003 OEM COA photo - http://www.google.com/imgres?imgurl=http://www.discount-software.ws/discount-software-images/office-2003-small-business-edition-oembk.jpg&imgrefurl=http://www.discount-software.ws/microsoft/office-2003-small-business-edition-oem.html&usg=\_\_UWwRE4eHpecLQJfV-YSf1773SCc=&h=593&w=570&sz=54&hl=en&start=18&zoom=1&itbs=1&tbnid=Pb-0LUqYcEyyRM:&tbnh=135&tbnw=130&prev=/images%3Fq%3Doffice%2B2003%2Boem%2Bcertificate%2Bof%2Bauthenticity%26hl%3Den%26sa%3DG%26gbv%3D2%26tbs%3Disch:1&ei=oANMTZOWCsL98Ab1iKGyDg

Fake Office 2010 Product Key Photo - http://techblissonline.com/microsoft-office-2010-product-key-and-license/

Fake Office 2010 package photos - http://stores.ebay.com/DAVAD-TECHNOLOGY-LIMITED/Fake-Microsoft-Office-2010.html

Fake- How to Tell if your software is Real - www.microsoft.com/howtotell/

Fake- Video demonstrating Bogus Win7 features - http://www.youtube.com/watch?v=hzqNNiOM0cs

Fake - Are there different types of software piracy? - https://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/lic_many_types_piracy.mspx?mfr=true

What happens if your product key is stolen? - http://office-watch.com/t/n.aspx?a=191&z=12 ****

If your product key is stolen, part 2 - http://office-watch.com/t/n.aspx?a=202&z=12

What to do when you figure out you have a bootleg / Fake copy of Office?

You ran into a problem where your Product Key no longer works. Using the following tips you figure that you have a bootleg copy of Office. What can you do?

1.       Determine how reputable the source is. Is it national retail chain or an individual selling on the internet?

2.       If they are reputable, contact the original vendor and ask for a replacement upgrade “Retail” version. Pay the difference

3.       If they are not reputable, and you used an intermediary source like Craigslist or Kagigi or such, contact them and report the vendor. They may have a refund policy or mediation service that will work for you

4.       If that doesn’t work,(don’t waste a lot of time on it, but do try it, contact your payment source: ie Credit Card or PayPal, and see if they will cancel the transaction and return the money to you.

5.       If you are feeling vindictive, you can report the ‘piracy’ to Microsoft using this page: chrome://ietab2/content/reloaded.html?url=http://www.microsoft.com/piracy/reporting/default.aspx.  With a little luck, MS will shut them down.  MS is serious about shutting down piracy, which is why legal users are put through the bother of the activation process.

Note: if you did buy a bootleg copy, don’t expect MS to refund your money or give you a replacement Product Key. Bottom line is that you didn’t pay them any money in the first place, so they don’t really “owe” you anything.

If these tips can't help you to confirm it is bootleg, do a phone activation. Don't enter any information, wait until the phone system offers you the option to talk to a "service" rep. Explain the situation to them and ask them to explain the exact reason why your activation is failing. They do have this information. If you are not satisfied with their explanation, calmly ask to speak to a supervisor.

“Windows License Locked!” "This copy of Windows is locked. You may be a victim of fraud or there may be an internal error," - Blue message box -http://www.computerworld.com/s/article/9215711/Ransomware\_squeezes\_users\_with\_bogus\_Windows\_activation\_demand?source=CTWNLE\_nlt\_pm\_2011-04-11