I would with no doubt click reserve it. It has all or at least most bugs removed from problems with windows 8. They skipped windows 9 because of this. I have researched a lot on this and not everyone has got the chance for this free windows 10 already.
It is of course best if you have a touch screen (maybe a reason to get one now) but brilliant without as well because if the integrated desktop so no messing around. From my research windows 10 should be great and you have better security build in also speed is excellent and it also clearly state that anything you already have installed on computer will be compatible.
So you should not have any problems with anything here. If it is not compatible then my understanding is there is a build in feature to support old formats. BUT this is from windows 8 so not sure now that you will make a big jump from windows 7. But I would recommend you to do it I have just myself opted in and made reserve.
Also it will not just install it straight away as its not ready until end of july more precise its 29th July. And it will only reserve it if you decide this. When it is ready you will only get notification if you want to make upgrade and install windows 10.
UPDATE:
Just adding specs required for that upgrade which is important to know for OP and other members here at casinomeister also more info at microsoft website link above:
Processor: 1GHz or faster
RAM: 1GB (32-bit) or 2GB (64-bit)
Free hard disk space: 16GB
Graphics card: Microsoft DirectX 9 graphics device with WDDM driver
A Microsoft account and Internet access