If the copies of all your software are legit, in theory there should be no limit to the amount of times you reinstall them. They recognise the motherboard, not the OS (AFAIK).
If you are really worried about it you could always take an image of your system as it stands at the moment. IMHO you should do this periodically anyway in case Windows becomes irreparably damaged.
You need (ideally) an external drive (if you have a spare HDD drive you can buy a USB enclosure very cheaply) and a piece of free software. I use Macrium Reflect Free, but EasUS ToDo Backup is also free and they are both easy to use.
They take images of your whole hard drive, so they are backing up both your Operating System, registry, settings, programs browser bookmarks and of course your data. You will be able to restore so it looks exactly like it did when you made the image, right down to your desktop picture, shortcuts etc
Be aware that it provides a snapshot only, so you should continue to run backups of your data in the normal way. These programs enable you also to make a bootable disc so if Windows gets corrupted and your PC will not boot you can boot from the CD you've made which gets you into a "cut down" version of Windows where you can browse for the image you've made and restore from there.
Just Search for Macrium Reflect tutorials (or EASUS ToDo tutorials) on YouTube to see how they work.
**Important** Make sure you verify the image when you create it, otherwise it will not work.