IRFANVIEW MINI GUIDE:
Get Irfanview free at:
https://www.irfanview.com/main_download_engl.htm

CROP:
Draw mouse line around portion to crop.
Adjust by pulling edges.
EDIT >> CROP SECTION or CTRL-Y

BRIGHTEN:
IMAGE >> COLOR CORRECTIONS or SHIFT-G

Watch out for CTRL-G which is GRAY SCALE
Use CTRL-Z to get back out of GRAY

I work mainly with CONTRAST and GAMMA CORRECTION
CONTRAST about 30, 40 or 50
GAMMA CORRECTION 1.30, 1.40, 1.50
Use that as a guide and zero in to perfection as you see it.
Experiment with the other settings on a crap image.

SHARPEN:
IMAGE >> SHARPEN or CTRL-S
Multiple sharpen till white sparkles appear and back up with CTRL-Z

AUTO ADJUST COLORS:
IMAGE >> AUTO ADJUST COLORS or SHIFT-U

RESIZE:
IMAGE >> RESIZE/RESAMPLE or CTRL-R
Select your requirements
I use 72 DPI (dots per inch) for my game images.
Larger to smaller has no resolution problem
If you stretch a small image too far you get resolution problems.
Sharpen as required. Some just don't work out well.

CANVAS SIZE:
IMAGE >> CHANGE CANVAS SIZE or SHIFT-V
Pick the setup you need.

BORDER:
IMAGE >> BORDER/FRAME
I pick COLD and dick around with colors and sizes.
The thumbnail is not to scale.
I alternate 2px black and fatter colors .. 20 to 50 or whatever.
You can get 8 borders by doing it twice.

SAVE/SAVE AS:
Normally use JPG.
For see thru portions use PNG with transparency selected.
Moveable images are GIF.
ICO makes icons ... keep them about 64 px square, usually with borders.
[You can right click on desktop folder properties and change icons.]
[You can get raw icons and other images at  https://www.google.com/imghp?hl=EN]
That's about all I use.
BMP is super resolution and big.

EDIT >> SHOW PAINT DIALOG or F12:
Lets you paint a pic or re-color sections.
The text is not great .. I usually use another prog for that.
You can draw red arrows with LINE to point stuff out in a presentation.
FILL is good for PNG transparent backgrounds ..
Set tolerance high, but don't bleed nearby colors.
You will get crappy edges on low tolerance.

Check out all the menus .. I found uses for FLIPS and PANARAMAS

The tech guy at the store can usually get data from the old drive onto the new one. The app programs can all be reloaded. Its the stuff you created that's tough to lose. You can get an external hard drive as a backup. I have some of my created stuff on USB thumb drives. I've also had my windows crash about 5 times. There's a way you can reinstall it and leave your old personal files untouched.