Welcome to the Dell Community @Ho2011 

To better assist you, the members and I would need the exact model number of your laptop/desktop???

1. Identify your Dell:

https://www.dell.com/support/contents/us/en/04/category/product-support/self-support-knowledgebase/l...

1. Go into your BIOS.

Power-on the system and start tapping the F2 key to enter System Setup.

1. In Windows:

Hold down the” Windows “key and tap the “R “key.

Then type msinfo32 and hit enter.

Best regards,

U2

Hi there ! It’s Inspiron laptop 5110 . 

Thank you , I fixed it , when I opened I find the LCD cable was loosing , so I made sure is well connected. And it turned normally, I’m looking for the RAM , because I think I damaged it as I was pressing unnecessary buttons , can you suggest me a link to purchase some ?