My memory on my computer is low, how do I fix this?

You can usually add more memory (physical) or free up hard drive space to gain more virtual memory. Or go to a larger hard disk drive.

Can I ask why you think it is low?

By memory do you meed RAM or Hard Drive space?

Here are some tips...

If it is a oldish computer:
-Install more RAM to speed it up a little. RAM is like a schools playground, the more RAM(playground) the more kids(programs) can play in there at one time. Startup is normally not affected but once windows is loaded you will see a difference.
-Uninstall all unused programs, printer and so forth...
-Move your personal files like music, photos,. to an external hard drive. If you have a lot of personal files, once move to an external hard drive normally greatly improves speed. Defrag after moving.
PS: REMEMBER, external hard drives are great for backups but the too can break or become faulty.

If your computer is newish:
Installing RAM and transferring. All personal files to an external source can make a difference but the chances with new computers are that it's either 2 or more anti virus-like programs installed or there is just no anti virus installed and a virus is hogging up memory...