I installed Ubuntu 18.10 two days ago on my laptop which is old one (4 GB RAM and 500 GB HDD). After installing finished, and the first boot it went well. I installed all the necessary software I require like chrome, xampp etc. It was quite smooth but after two days later that means today it just stuck in bootloop (Ubuntu logo which has five white dots and they turn orange, I think it's loading animation) I don't know what to do. Can somebody help me please? Thanks.