Dell XPS 400 Uprgade.

The answer to your memory question can be found in the Service Manual for the XPS 400 <ADMIN NOTE: Broken link has been removed from this post by Dell>.  It will accept a maximum of 4 GB of DDR2 667 MHz.  A good place to begin is www.crucial.com and use their memory configurator application to get you a part number.

You can certainly install Windows 7 on this machine, but do not expect to be able to use all 4 GB.  The chipset is limited to that amount of addressing space, so even the 64 bit version will not be able to use 4 GB of memory.  Unless you have a need for the later version of Windows, however, I see nothing wrong with using Windows XP.  I'm still using that OS on my XPS 410 with 2 GB of memory and it performs very well.  If you are concerned about security issues you might consider the 32 bit version of Windows 7; that will run most things that work with Windows XP a bit easier than attempting to run the same applications on a 64 bit version of Windows 7.

With regard to upgrades, that would depend a bit on how you use the computer.  I use mine for general purposes and play very few games.  I have the nVidia FX 8600GT video card which is becoming quite dated at this time, but it is more than enough for the things I do.

From the Crucial. com information on the  XPS 400:

Memory Type: DDR2 PC2-5300, DDR2 (non-ECC)

Maximum Memory: 4GB

Slots: 4

Each memory slot can hold DDR2 PC2-5300 with a maximum of 1GB per slot.

I would also check out Microsoft's Win 7 Upgrade Advisor to see what hardware/software/driver issues you may run into:

windows.microsoft.com/.../upgrade-advisor

Thank You Jack Shack and mpo...

Btw, I don't mind XP. I'm thinking of at least Vista as a upgrade, even though allot of people skip over vista. You've helped me out because the Ram thing is an issue for me. My Dell is definitely slowing down as it seems like more and more sites on the Internet require more resources from my PC. I want to do be able to do a clean install and upgrade my ram at the same time. I understand that my chip set will be an issue with some versions of Windows. I believe My  Processor is still decent. So I really don't think its a speed issue as much as its a ram issue (resources).

We are happy to have helped.  Good luck to you!

Hi all!  thanks for the info as Ive been looking for the same kind of answers. I also have the same Dell XPS 400 computer with only 1gb of ram, except my processor is a 3.0ghz pentium D if that makes a difference. 

Now should i just add 3gb more of the specific ram, and upgrade to windows 7. or if i do upgrade to windows 7, can I add more than 4 gb of ram?  From the information im getting, im not sure if the max the computer can handle is 4gb no matter the operating system, or can you bring it up to 6-8gb if you upgraded to windows 7?

Sorry if this is what you all basically just answered already, as I am not the most computer savvy person in this area.

please let me know, thanks!  Scott

Your XPS 400 is limited to 4GB, as the chipset itself (which contains the memory controller) is limited to 4GB - the OS cannot change the fact that the system can't use it.  For future reference, if a system does support more than 4GB, the operating system must be 64-bit to use more than 4GB of RAM.

I've got an XPS 410  that has been upgraded over the last couple of years to one that rivals any dual core in the house.

Memory:    4x1gb Crucial DDR2-667            

GPU:         Gigabyte GT4300 low profile

CPU:         Core2 E6600 2.4ghz

HD:            OCZ Vertex3 90gb SSD

OS:            Windows 7 Home Premium

I started with 2g of memory about 2 and a half years ago.  I know the mem bus is only 533mhz., but the 667 was cheaper and just runs at the lower speed.  I added the original 2x512mb to the 2x1gb until I had reason to add more.  Unfortunately, the cost on that pair went up $10 in the intervening years.  The 3gb seems to be a sweet spot for XP, in my non-gaming experience.  Due to the $50+ cost on a pair of 2gb modules, I plan to stay with 4gb for the forseeable future.

I added the CPU last year after some help from Bev on this forum.  It wasn't a huge upgrade from the original core2 @1.8ghz, but at $45 off ebay it was a good learning experience and produced minorly noticeable results. 

The graphics card was a Christmas bargain($40 after rebate) that smoothed out video downloads.  I chose the low profile low power board with an eye toward eventually using it in a HTPC I'd like to build out of an old 530S in the closet. 

The SSD was a birthday gift two weeks ago and I am completely blown away by this under $100 upgrade!  I took the opportunity to install Windows 7 on the new drive and just migrated my programs and devices one at a time, keeping the O.E. 250gb HD for storage.  WEI scores are 5.8 for CPU and memory, 6.7 for both graphics catagories, and 7.7 for the SSD, even on a restricting SATA2 mobo.:emotion-2:  My computer now boots to desktop in around 45 seconds, just as quickly as my year-old Inspiron15 core-i5 laptop!

I'm no computer tech, but I've been able to get a lot done for a little money by researching on forums like this and watching for bargains on Newegg and other sites.  Good luck!!:emotion-21:

Wow.

Too bad it takes you so long to get an answer.  Then you get a wrong answer!

Please people! if the only thing you know is from reading a book, please don't pass yourself off as an expert.

Just to let you know I just added 2 2GB modules to my xps 410 for a total of 6GB.

Specifically I added the cheapest I could find.  Corsair Value ram VS2GB800D2.

Others have successfully gone up to 8GB total.

I have also installed Win8 64 bit (from 32 bit) - clean install. just need to download from a 64 bit machine so you get the right iso.

Hello DORIANPC,

I know that this is an older post, but I have an XPS 400 with BIOS A07 and Window 7 64 BIT. When I go to Crucial.com it states that the most RAM that I can add to the unit is 4GBs, which I did years ago. Are you stating that I can actually upgrade this to 8GBs of RAM? I thought I read that the BIOS controls the max RAM allowable even if you have a 64BIT O/S? 

You state that you were able to upgrade to 6GB of RAM on your XPS 410 when you posted in 2012, were you able to upgrade to 8GB of RAM since then?

I do plan to upgrade the CPU to an Intel Dual-Core 3.6Ghz/4M/800 CPU Processor SL9AP LGA775 Pentium-D 960 800Mhz.

Thanks,

Nothing wrong with an old post that has the right answer. 8GB will work, at the time i didn't want to spend the extra 40 bucks. Right now i am typing on the XPS 410 still with 6 GB. - I have 4.1 GB available (haven't started zipping up files to my NAS yet, figured I'd answer you first.).

All the memory makers produce the same garbage, Usually they get the parts matched up right. You may have to be careful about putting the ram in and make sure it is seated, couple of reboots ( go into the bios until it is recognized) Dell bios won't control the RAM clock, it's determined by the chipset.

Make sure you match the clock speeds and CAS timings on RAM you buy to what you have (or a little faster)

By the way, I would do a SSD upgrade as a boot drive before a processor upgrade.  You WILL be happy.

XPS 400 and XPS 410 are different machines.   8 Gigs works in both machines.

That sounds awesome! I have an XPS 400 that I've been upgrading...got it off of Craigslist for $40 with ton of accessories! So how do you get 8GB of RAM to work in it? And how much can go in one slot?