I cant install this update please help

KB915597 is a generic KB number, applied to ALL Defender and MSE updates, and can update anything up to 8 times a day!

it has no relevance to the general state of your system - ignore it.

If you go to Windows Updates, what does it show being offered?
If you go to Update History, what is the last Failed update? Does it show as having been installed later?

the latest failed update was a monthly quality rollup update called kb4534310

OK- that's the January 2020 update, so not too bad
Does KB4534310 still show in the waiting updates list (it shouldn't)
Does kb4537820 show in the waiting updates list?
What actual updates do still show in the list?

We can ignore the 915597 update, so that leaves us with 3 to worry about...

The oldest one is https://support.microsoft.com/en-gb/...er-for-windows

so that's the one we need to concentrate on.

Please reboot, run a new Search for Updates, then unselect everything except that one - and try installing it.

If it errors out, what is the exact error message you get?

i think i have installed it previously, but i uninstalled it again since i didnt need framework 4.8
is this the last update there is?

4.8 is effectively an upgrade, rather than an update - and there will be updates to it that will come down afterwards.