Hi jabirmawalimu,
I understand that you are looking for the software and drivers for your LaserJet printer. I will try my best to help you find this. In this link for HP LaserJet 1020 Printer Drivers choose your operating system and click the next button. Scroll down then click on 'Driver - Product Installation Software' then click on the 'HP LaserJet Full Feature Software and Driver'. On the next page click on the 'Download' button. I suggest that you save it to your computer and then run the install.
I hope this helps, let me know.
Thank you,