Can I use product images from official websites?

No amount of excuses can make stealing the content of others legal. While there is something as fair use, you cannot use an entire image or other media which is created by someone else and not licensed for your use.

There are three common ways to obtain product images:

• Take your own photos. If you have access to the product this is easiest. You may even pay for someone to take photos for you and they are many photographers who specialize in product photography. The advantage is that you do not really wait for anyone and you will have unique images that suit your site quickly.
• Get images from the maker. Write or call them up. Depending on the company, you can get beautiful high-resolution images within hours, they may ignore you completely, take weeks or even ask you tons of questions and request information from you to establish who you are and what you are doing. I have several product websites and I can tell you I've gotten all those responses and more variations.
• Get images from an affiliate program. If you are promoting a product through an affiliate program, there sometimes is material available for this purpose. The dying Google Affiliate Network is particularly good for this but Amazon also has product images, only much smaller ones. In either case, the affiliate interface makes it clear which photo you can use and gives its direct URL. On Amazon it says 'save this image to your server' when they do not want to be hot-linked,

Promoting a product of another company does not mean you do not require the rights to use their content. You will need to contact Acer and ask permission, unless within the terms of use of their website says that you can (Which I doubt).

Sadly its not a matter of if your promoting a product or not, for example Video Trailers even though they are promoting a movie they still require an publishing license, as well as Lyrics for Music. This is the same for some posters and stock images of items, some companies require you to purchase a license - It's an monopoly and everyone wants their cut.