Use it as your system device / C: drive, that is the best place. Please remember, you don't defrag an SSD, Windows recognize it and defrag it neither, an SSD should be optimized. I think you will gain a lot performance and be very happy with it.
I don't know what defrag is , i may be wrong but i think i used nero video burner on it . So think i would have installed windows on it , i just want to know if it's worth investing in a decent size Solid-State Drive or an internal hard drive .
lots of people use solid drives as their system drive yes... the C drive is where Windows is installed and normally you want that drive to be as fast as possible but older drives don't cost as much so they make fine storeage
worth getting = about 250G is where most laptop users like a c drive +[at least] 500G for a system that does editing or needs to run on battery while you travel = yes worth it i personally like the 120G solids for my laptops and I shub a 1-2T storage drive too which does everything i need at less than 1/2 the price
To access data on a harddisk, the readwrite heads have to be positioned on the track and after that the track must be spined to the position the actual data of the file is located, that are the the seek time and rotational delay. The benefit of solid states drives is that the seek time and rotational delay are zero.
The part that benefits the most is Windows itself on the C: drive. You won’t get that benefit by using a 1TB SSD and adding there more and more non system files.