Athlon II X2 in an AM2 socket?

I think it will fit but there may be a voltage/wattage problem as they require more power, you may fry your CPU. Don't be so tight with your money, it's only £40/$70 for a new AM2+/AM3 DDR3 board.

Ok, I'm going to say no but my reason is a real one, not some BS about power because any AM2, AM2+ and AM3 CPU will work in an AM2 socket as long as its TDP is 95W or less. The problem is that it's a Dell. Generally, brand-name desktops have their BIOS hard-wired to only support the CPU that the computer came with because the "brand-in-a-box manufacturers" don't want you to upgrade, they want you to buy a whole new computer. There's a very good chance that your BIOS will not support any CPU other than the LE-1660. Update your BIOS and try it out if you want but it may not work no matter what you do. If that fails, then just get this motherboard and install it there:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Really, really though, the fact that you have a Dell tells me that you don't really know how to build and installing it on a motherboard twice and having to use fresh thermal paste may be dangerous for a first-timer. It would probably be best just to use the new motherboard regardless.  

Okay, I'm just wanting to replace my CPU with a 45w athlon x2 or II x2. I've done my research and I am going to get either the 2.6ghz 5050e (AM2) or the 3.0ghz 250e (AM3, but supposedly compatible with AM2). (Don't want to bother replacing my cooling components besides paste obviously.) How can I check my mobo to see if its really an AM2+? IOBit System Information is telling me its an AM2 - though it might be describing the processor. And what CPU swap have you done with this mobo?

Thanks for the help.

Okay, well here's an idea. Because I'm a complete amateur at mobo/cpu tinkering, maybe I just leave that part alone, deal with the 2.8ghz single-core, and hope it doesn't bottleneck my HD5670 too much? Or is that card a waste of money with my current CPU?

Any recommendations on what video card would be ideal to pair with my athlon le-1660? Currently have an HD4550. I want to play borderlands and mass effect on high at near-60fps at 1024x768.

I think that a HD5670 would be a very nice match.The Athlon le-1660 was a potent single core CPU albeit older and not quite as fast as the newer Sempron Sargas single core CPU's.
http://www.cpubenchmark.net/cpu_lookup.php?cpu=AMD+Athl...

The HD5670 is a nice inexpensive graphics card and quite a substantial improvement over a HD4550
Here is the graphics card hierarchic chart.
http://www.tomshardware.com/reviews/gaming-graphics-rad...

The HD4550 was even more poor than a HD 3650 which I used in an Athlon 64 3400+ single core system a while back.
So definitely it would be a major (and worthwhile) inexpensive improvement.

I'll make do for now, because my budget is less than $200 at the moment. And I don't want to risk buying a processor that isn't going to work because of Dell's BIOS. Eventually I will replace the motherboard, get an Athlon II X2 250e or 265, some ddr3 1600 ram, and a DVI monitor. Til then I'll be fine with just the HD5670.

Thanks guys.

Best answer selected by jessterman21.

Got the HD5670, and unfortunately on new games, my athlon le-1660 is definitely doing some bottlenecking... I've tested it on Portal, and the Steam demos for Mafia 2, Just Cause 2, and FEAR 2 - can't get above 20-30fps on 1024x768 for anything... I did find out that the 65w athlon ii x2 250 (rev. c2) is compatible with my Dell mobo, so we'll see what 3.0 GHz and 2MB L2 cache can do for me.

UPDATE!

The CPU swap works!!! To everyone who owns an inspiron 546, flash your BIOS and you can upgrade to a better AM3 CPU!!! (i.e. Athlon II x2 - Phenom II x4 945)

Anyways, the Athlon II x2 250 works admirably - at least twice as good as the single-core Athlon le-1660 I had. It was so easy to install, too. Games all run smoothly (even at 1440x900), except the ones where my HD 5670 isn't quite up to the task.

One side note, the le-1660 did a killer job for a single core, (only 10fps less on average than I'm getting now) much better than any single-core Pentium 4, but anyone calling themselves a gamer should definitely get a dual-core at minimum.