Hey there, Adardon.
Here are a few options, which could make this possible:
1. You have installed your OS on a separate partition (having your files on a different one). If this is the case you should be able to clone just the Windows associated partitions over to your SSD.
2. Transfer the files you want to keep to another drive (either external or internal one), delete those files form the HDD so that the used capacity is less than the total capacity of the SSD and clone your OS (
How to Migrate to a Solid-State Drive Without Reinstalling Windows), reformat the HDD (so that you have a fresh secondary storage drive) and transfer the files you need back to it.
3. Make a clean install of your OS on your SSD (with the HDD disconnected during the installation process). After that you could again transfer the files from the HDD to a different drive, reformat it and put back everything you might need.
Hope that helps.
Boogieman_WD