They are very similar speced machines at very similar prices. I would confirm that both machines are using '800mhz' front side bus and not the older '533mhz' front side bus. They probably both are the newer '800mhz front side bus' - but worth checking anyway.
In comparative terms
Computer A advantages
Slightly faster CPU (3.2 vs 3.0)
Better Grpahics card (if you play 'new' games the 5700 will make a big difference than the 5200 in computer B)
Littel bit cheaper
Computer A disadvantages
No mention of brand of monitor. There can be quite a difference between a cheap TFT monitor and a 'quality' one. The one with computer A may be a decent enough monitor but without details as to who makes it this is hard to tell. Computer B on the other hand list a brand name (philips).
No mention of the brand for speakers. Again very cheap speakers can be terrible. Computer B list a maker for its speakers and actualy the speakers they include are pretty nice with a retail price in the UK of around £75 inc vat (
http://www.overclockers.co.uk/acatalog/ ... akers.html)
Normal keyboard and mouse vs 'wireless' keyboard and mouse on Computer B. Personaly I use a wireless keyboard and mouse and prefer it to a wired one.
All in all there is not much difference between thse two models. You might want to ask what speed and what 'format' the RAM memory comes in as well as how many slots there are on the motherboard. You could have 512MB of ram in a single memory stick or in two 256MB sticks. If it is in two and the board only has two slote then any upgrade to the memory later would then require 'throwing away' one of the two 256MB memeory modules to make space for the new one. If the existing memeory is on a sinlge 512MB module or the mother borad has more than 2 slots on it then memeory could be added to the existing without having to lose any of the existing memory. This is also a slight performance advantage to using two 256MB memory stick vs a single 512MB stick - if the motherboard supports dual channel DDR memory. However this improvment is fairly minimal in most PC usage.
Personally I build my own PC's and generaly go for AMD processors rather than Intel as you tend to get more power per pound with AMD. Below is an example of what kind of system you could build and the kind of price you can get the components for in the UK. I have built many such systems for myself and others and if you were interested I would be happy to build one for you as well. I am due to go to the UK at the end of the month and could get all the parts there except the monitor and case and speakers (which are to big to carry back). The below then is an 'example' of what a similar system would cost if you 'built your own' and sourced all the parts in the UK. The real beauty of a 'build your own' approach however is that you can tailor the PC to your exact requirments. I will show some alternatives as well to highlight this point.
(all components from
www.overclockers.co.uk)
Asus A7N8X-X nForce2 (Socket A) Motherboard (MB-028-AS) 1
£35.95 £35.95
AMD Athlon "Barton" XP3000+ 333FSB (Socket A) CPU - Retail (CP-035-AM) 1
£99.95 £99.95
GeIL 512MB (2x256MB) PC3200 Value Dual Channel Kit CAS2.5 (GE5123200BHDC) (MY-004-GL) 1
£56.00 £56.00
Sony CRX320E 52x32x52x16 CDRW/DVD Combi Drive (White) - OEM (CD-019-SO) 1
£23.00 £23.00
OcUK ATI Radeon 9800 Pro 128MB DDR TV-Out/DVI (AGP) - Retail (XR98-C3) (GX-005-OK) 1
£109.95 £109.95
OcUK Value Floppy Drive - Silver (CD-001-AP) 1
£6.50 £6.50
Samsung SpinPoint P SP1213N 120GB ATA-133 8MB Cache - OEM (HD-008-SA) 1
£51.00 £51.00
Viewsonic VX715 X Series 17" TFT Monitor - Black/Silver (MO-007-VS) 1
£245.00 £245.00
AOpen H500A Midi Tower - 300W PSU (CA-001-AO) 1
£39.95 £39.95
Creative Inspire 2.1 P380 Speakers - Retail (SP-020-CL) 1
£28.95 £28.95
Microsoft Wireless Optical Desktop v2.0 - OEM (KB-018-MS) 1
£27.00 £27.00
Creative Modem Blaster V.92 PCI - OEM (MD-003-CL) 1
£9.95 £9.95
Subtotal £733.20
Shipping (Amtrak Next Day (Mon-Fri) - UK Mainland) £17.75
VAT £131.42
Total £882.37 (UK Pounds)
The above system is very 'comparable' to those you listed. It uses the AMD XP3000+ CPU which for most applications is somewhere between the intel 3.0 and intel 3.2. It has a much better graphics card spec than the two examples you give (ATI 9800pro) - which if games are of import to you will make a major difference (especialy over the nvidia 5200 based system).
However you could tailor the above spec to your needs. For example if you did not care about games then I would suggest going for a version of the motherboard above with integrated graphics and forget the Radeon 9800 graphics card (which would save you £115.78inc vat of the prices above). Also you may not want a modem (if you connect to internet via BB/DSL for example). Or you might want a DVD burner. With a build your own system you can chose exactly what you want.
As I say I would be more than happy to obtain the parts (that I can carry) in the UK for you, as well as either help you assemble them or juts assemble them myself for you. If you do consider this route you will need to check availability and price in the RoC of those parts that I can not carry from UK (monitor, case, speakers and keyboard if you want a non UK one). Also you may want to get a licsensed copy of windows XP, which is not shown in the prices I have quoted. There are alternatives to a licsesned copy of the operating system (windows XP) - but these are a little less than strictly legal. On the 'guarantee' front you will of course have the normal manufacvtuers guarantee on each of the items - ususaly this is 1 year but on some componets it is higher (the samsung HD have 3 year warranty for example).
Anyway what ever you decide I hope the above has been of some use and interest to you. There is nothing really wrong with either of the systems you list. To me they are little expensive - but then I work on UK prices and not RoC ones. Also I just would not personaly buy such a pre built system as I like to chose and tailor my PC to my personal needs.