How to increase the speed of my PC wihout upgrading new hardwares?!?

Uninstall or disable the startup shovelware. See task manager. Be careful not to uninstall or disable something your computer actually needs!

Turn off indexing for your drive.

Run the windows memory diagnostic with recommended settings.

Delete unneeded junk off your main hard drive. If it's a real hard drive (and not a SSD) then defragment it.

Don't launch a bunch of programs at startup (use setup.msi to see what programs are being started at startup and turn those off that you don't need.)

Don't run a bunch of programs in the background. (use Task Manager to see everything that's running.)

The only things you need running are your operating system (Windows) and your anti-virus program.

Don't use virtual memory if you can avoid it. If your computer only has 4GB of RAM, try to keep its total memory usage to 4GB or less. Windows supports Virtual Memory, which allows it to use a small portion of your hard drive as RAM but this is VERY SLOW. By keeping your total memory usage limited to what your computer has in physical RAM you'll get much better performance.

Try a fresh installation. Computers get bogged down with programs. By reinstalling the OS, you wipe the hard drive and start over.

Get cable and get rid of the trash that bogs your OS down.