I have a laptop that has a 1.7ghz intel centrino processor and 1gb ram and a 14" screen.

Would it be worth upgrading to a 1.4ghz pentium dual core with 1gb ram and a 15.4" screen?

That all depends on...what you want to use it for....weather your current one does what you want it to do....and how much its going to cost you

the 'centrino' refers to the collection of components (CPU, GFX, WiFi etc) as a whole... what is the actual CPU? is it a Pentium 4? dual Core? Celeron? etc...

download CPU-Z ( http://www.cpuid.com/cpuz.php ) and find out exactly what it is you have currently...

and then, depending on that.... as sidbobs said above, depends what you need/use it for.

I downloaded CPU-Z and it says Pentium M 745 Processor.

Yes, it would be a considerable upgrade, but theres other factors to take into account like the speed of the RAM which will also be faster, the hard drive speed which will probably also be faster on the new laptop.. which will equate to a much nippier machine..

but the big question is, as above... depends what your using it for.

Erm, I would use it for web browsing, Using photoshop elements, Don't really play games, Not games that are too demanding anyway.

I would also use it for updating my websites and for storing photo's and music.

yeah, you will probably see and feel a huge difference in the two then... I would go for it..

I boosted my old 3 year old laptop with some more cheap memory.

Have you seen this at Tesco

Acer 5732Z laptop - £397 at Tesco

Acer Aspire 5732Z Laptop (Intel Pentium® Dual Core T4300, 4GB, 500GB, 15.6" Screen, Windows 7 Home Premium)
Catalogue number: 207-6879

http://www.hotukdeals.com/item/593673/acer-5732z-laptop-397-at-tesco

And here for a fuller spec.

http://direct.tesco.com/product/default.aspx?R=207-6879
.

Have you seen this at Tesco

Acer 5732Z laptop - £397 at Tesco

Acer Aspire 5732Z Laptop (Intel Pentium® Dual Core T4300, 4GB, 500GB, 15.6" Screen, Windows 7 Home Premium)
Catalogue number: 207-6879

http://www.hotukdeals.com/item/593673/acer-5732z-laptop-397-at-tesco

And here

http://direct.tesco.com/product/default.aspx?R=207-6879
.

Not bad, I don't think i would buy an Acer laptop though, Very unreliable.

I know a few people who had Acer laptops and fell apart.

the last Acer I had lasted 4 and 1/2 years before I sold it on to a friend, and its still going now (6 years on)

I too have had an ACER for over a year now and only problem is that it is too good for the price I paid! I got it for Blu Ray and DVD copying, never had a fault on it!
Software is good but a bit basic