Here are the completed sentences using the provided words:
Oh, no! I've accidentally deleted all the photographs on my hard disk!
Let me make a copy of these files before you transfer them to your computer.
The reason why your computer is so slow is that it needs more memory.
Is there a problem with the network? I can't connect to the Internet.
I need to buy a new mobile phone. I've spilt water on my old one, and it's stopped working.
Click on this link to go to the international site of the online store.
I think your computer has a virus. You'd better run a full scan.
What's wrong with the screen? It's been frozen for the last ten minutes.