|You said you have a 1TB drive, now you say you have two 500GB drives...it's not the same thing.|
If you don't know how to maintain your drives & don't understand the need for free space & for defragging, there's not much we can do to help. Other than dumping the recycle bin as mentioned by OtheHill, do you practice other forms of housecleaning? dumping files from the temp folder, history folder, temp internet files, etc? If you're constantly getting low disk space warnings, there's no way your system is performing as well as it could (or should).
"I dont really care about defrag or any of that crap"
Microsoft has an article called "5 ways to speed up your PC". The # 1 way is to free up disk space, # 2 is to defrag your drive(s):
5 ways to speed up your PC
You should also read up on partitioning: