Hi Ally,
Well it depends on what hardware was changed out in the computer during the rebuild. The Vista/Win7 license keys are tied to the Motherboard that came with your computer. It would certainly help to know the Make/Model of your computer, and whether it's a desktop PC or a laptop.
If the Motherboard was indeed changed out, you will have to call Microsoft to see if they will transfer your Vista/Win7 license keys to the new Motherboard. Just so you know, they rarely do this for free; so expect to pay $39-$99 or more for this service. The person or Tech who rebuilt your computer for you actually should have done this for you. Have you contacted them for the new license keys?
If the computer Motherboard was NOT replaced and is intact, but maybe your hard drive was replaced and maybe the RAM memory, then you can reapply the VISTA COA license key that's on the outside case of your computer. That's the Microsoft license label. The Win7 upgrade disc that came with your computer will usually activate for free using your Vista key. Sometimes, that Vista-->Win7 upgrade will ask you for a Credit Card, as Microsoft originally charged folks $14.99 US to perform the upgrade license activation. On most desktop computers, it's on the outside left or right side of the case, sometimes it's affixed to the rear of the PC itself where all the connectors or ports are (e.g.: video, ps/2 or usb keyboard/mouse ports, SATA, audio/mic etc.). If it's a laptop, the COA label is usually somewhere on the bottom of the laptop case. A problem I occasionally encounter is that since the COA label is on the bottom of the laptop, and if not protected with vinyl sleeve or plastic covering, the numbers are often rubbed or scraped off where all the digits, numbers and letters, can't be clearly seen.
This is not uncommon in laptops as old as yours which could be 7-8 years old since it came with Vista installed. If this is the case, you have 2 choices: (1) repurchase a new retail Microsoft Vista CD and key on ebay for around $90 US; or
(2) call Microsoft and have them run the serial number of your computer and see if they can lookup or reissue you a license key. They may have you call your computer manufacturer to do this, so it can be a bit of a runaround; 2-4 hours on the phone easily. The manufacturer will be able to run your machine's serial number, but due to the age of your computer, they may not want or be able to reissue your key or look it up for you and send you back to Microsoft. Or they will tell you to do #(1) which is to just buy whichever OS you want and do a manual rebuild (say Win7 since you mentioned that's what you upgraded to; $90-$150 on ebay).
So you can see we need additional information about your computer from you; but it's going to be a challenge in any case. If you haven't done so, you may need to enlist the help of your local licensed Computer Pro to sort a situation out such as this. And you will probably have to pay him for this type of assistance as it's very time consuming.
The real issue you have is whether or not you wish to pay $40-$200 or more to get this computer working again with a legit license key so Windows7 will activate over the Internet. If you are outside the US, it could be 3 times this cost or more; $120-$600 US. In that case, you might just consider replacing this old computer, or just load a free version of Linux on it such as UbuntuLTS14.04, Zorin, or Slax.
Hope this proves helpful. We can advise you further once you post back your machine specs.
Regards,
<<<BIGBEARJEDI>>>
