Hi all,
 
I have been playing Star Trek Online on my laptop:
Intel  Dual T3400 2.16Ghz
4Gb Ram
Integrated Intel Graphics - Yuck!
Windows 7 64Bit
 
It is playable but far from great. I decided to re-setup my old (self built) rig from 2004.  (Decided to go with consoles once that became obsolete).
Intel Pentium 4 HT 3.6Ghz
1Mb DDR2 RAM
ATI X800XT-PE 256Mb PCI-E Graphics Card.
Windows XP

Any way I tried Star Trek on that and it ran surprisingly  well, much better than the laptop. The problem is my graphics card. It is on it's last legs and keeps locking up the system after an hour or so. I am saving up to build a new rig, but expect that to take at least another year.
 
As you can see I have been out of the PC Scene for quite a while. Not wanting to spend a lot I have been looking at a cheap £40 Ati HD5450 512Mb to replace the X800XT. Can I expect this to offer at least the same performance as the X800XT? Will only be playing Star Trek Online and re-playing the old games I bought around 2004. Not entirely sure it is compatable with my current system. Can someone point me in the right direction. 
 
Edit:
Side note: Another reason I am drawn to the HD5450 is that it offers passive cooling. The X800XT was always a noisy beast and I just can't live with the noise under full load! Have cards got quieter over the years?
 
Thanks

Sounds like the 5450 will do you good in this case, though it's up to you whether you want to spend that money now for the card or hold on to that bit and use it towards the full new rig.  
As for noisy cards, they still vary from card to card. There are some that are much louder than an old X800XT, but I've found that, for the most part, cards have quieted down.

The big advantage of the 5000 series cards from AMD is that they are DX11 compatible.  I know you're not really looking for a gaming card, but that's still future proofing.

 Just an update, the old rig has finally become rediculously unstable. Looking to build a new rig up over time. Hoping to start with this as a base: 

AMD Phenom II X6 1055T 2.80GHz (HDT55TFBGRBOX)
Asus M4A89GTD Pro/USB3 AMD 890GX (Socket AM3) DDR3 PCI-Express Motherboard ( M4A89GTDPro)
Corsair HX Series 750W Modular ATX2.2 SLI/Crossfire Compliant Power Supply (CMPSU-750HXUK)
Corsair XMS3 4GB (2x2GB) DDR3 PC3-12800C9 1600MHz Dual Channel Kit (CMX4GX3M2A1600C9) Listed as i3/i5/i7 but plenty of people running this with above mobo, tweeking with Bios. Listed AM3 memory is more expensive for some reason. 

Corsair CWCH50-1 Corsair Water-Cooling™ High performance CPU Cooler (CWCH50-1) Hoping will allow upping cpu if needed at later date, and fingers crossed quieter than stock cooler.
NZXT Beta Evo Midi Tower Gaming Case - Black (nzxtbevo-001bk)

The above comes to £574.70 delivered which is the cheapest I can find so far.

Now the mobo has integrated ATI Radeon HD4290 chip which I am hoping will be adequate for Star Trek Online. I will be using my Samsung 720P TV (Yeah I know!)
I will be using my current 250GB Hard drive and DVD-RW plus some of the current case fans if needs be. Oh and using Windows 7 Home Premium 64 (already have).

Further upgrades down the line when more funds available:

1TB Hard Drive
Another 4Gb Memory
Graphics card of some description. May wait until HD6xxx series and assess the options then.

My main question is whether the HD4290 will be adequate to solidier on with or do you thin a separate HD5xxx lower end £100 ish is worth the purchase now, with the view to upgrade realisyicaly next year? Any suggestions?
Also with 750W be enough seems to tick all the 12v rail amps etc, I can't envisage multiple GPUs anytime soon, if at all but want potential for modest overclocking?

Just get a GTX460 1gb later on, intergrated graphics is not something you will use for gaming unless you want to play at really low settings.

Thanks for the quich reply. I have the option to get a VTX ATI Radeon HD 5770 1024MB GDDR5 (Clock speed 850 MHz) for £111. Worth it to be getting along with at 720P? Won't be playing crysis just Steam games, mainly source engine. So close to just clicking buy :)    

" Thanks for the quich reply. I have the option to get a VTX ATI Radeon HD 5770 1024MB GDDR5 (Clock speed 850 MHz) for £111. Worth it to be getting along with at 720P? Won't be playing crysis just Steam games, mainly source engine. So close to just clicking buy :)     "

Excellent. I opted for the card  as it was a limited stock deal and 5 had already sold during my  umming and ahhing. Can stop worrying now. I can actually get value from STO now (lifetime sub) without it chugging. I enjoy it, scratches my sci-fi/ space combat itch. Could never get into Wow during the trial period didn't take to the fantasy setting. Also looking forward to revisiting some older games I own. 
 
Thanks everyone for your replies has helped alot.