My motherboard is Asus P8B75-M. It doesn't have Intel Smart Response. But recently I bought a SSD. Since I mostly use linux I have Linux installed in it. But can I use it to speed up Windows also? How? I don't have Smart Response... (I run Windows 8.1). The SSD is only 64GB.
It would help to have the exact SSD model.
Did you receive with it any bundled software such as Dataplex?
If not, one alternative to Intel Smart Response Technology is FancyCache, now in 180-day beta testing period. The drawbacks are firstly its SSD cache is non-persistent cache and gets reset in a reboot. Secondly, if using write caching with deferred writes you run the risk of data corruption if the system crashes. Thirdly, using the SSD as a cache will tend to wear out the SSD quicker. Fourthly, beta software is always risky.
The most I think you can do with an SSD which is too small to install Windows, is to store on it your documents. You can also install your most-used applications (installing them in the Program Files folder is just a convention).
If your SSD is large enough, you could partition the SSD as two logical drives, and put Linux on one, and install Windows onto the other. There are guides on the internet that describe the partitioning and install process for Windows. Just Google them.