How can I make my computer run fast? Should I go for computer repairs in Adelaide?

Since you didn't bother to tell anyone what OS or any of the other specs of your computer...I recommend using google to find options for cleaning out your computer and speeding it up that pertain to what equipment and software you are utilizing.

- but if it is a windows machine you can start by running Disc Clean Up. (located in administrative tools or windows system tools and it is free)

Answer depends on a lot of things:

CPU speed of your PC.If it was originally slow it will always be slow.

If it was fast you need to run anti virus and anti malware programs

Have enough space on HDD.Remove not needed files and programs.Run Disk Cleanup.

Defragment HDD if needed.

Couple things more.

first optimise it , and turn of autoloading programs you dont need  then see if it improves , or just sell it and get a new one .

if you don't really have any virus or malware or background task on task manager but your computer still slow, the problem will be on hardware, 

your cpu could be old and slow, and your ram, if your ram is 1 or 2 gb, it's slow

Reset it.                              .

im a pc technician and going to tell you, the first best thing is add a 2.5 ssd to older computers if compatible with sata!

Since you didn't bother to tell anyone what OS or any of the other specs of your computer...I recommend using google to find options for cleaning out your computer and speeding it up that pertain to what equipment and software you are utilizing.

- but if it is a windows machine you can start by running Disc Clean Up. (located in administrative tools or windows system tools and it is free)

older computers literally can not be made to 'run fast' -- modern websites, operating systems, and programs became larger, leading to slowing down.  you can't catch up to the more modern, faster hardware without replacing your computer.  other things to try -- delete junk from the startup system and run a quality anti-malware program

why notepad text is interfering, when will you correct it?