Help with PSU/New Graphics card

[wellabroad]

Hi everyone, this is my 1st post so please be gentle with me as im no computer guru
Im looking to upgrade my Graphics card but want to keep the cost down but am worried about my PSU (info to follow) i have read that you can run a higher Wattage card than allowed by the current PSU without having to upgrade. Cost is my main issue.
The tech/info bit
AMD Sempron 2gz dual core 2200
4Gb RAM
GeForce 9200 (think its built in)
ACPI x86-based PC
PSU. FSP Group, FSP250-60HEN
DC out - + 3.3V, 17.0A + 5V, 18,0A + 12V1, 8.0A +5Vsb, +3.3V and FSV= 115W max, total not to excide 250W 14.0A,

Other info,
MCP78PVM-PM, it says inside PCI Expresss 2.0 and also HT5200
Its a Packard Bell pre=built case with lots on room inside for expansion

So what im looking for is can i run a better Graphics card than i have now and if yes some pointers as to what card i can get. Budget is around the 100GBP mark
Many thank in advance for your help

 

[wellabroad]

Hi and thanks for the quick replys, yeah i know its not a great system but all i could afford at the time, can you explain what B grade refers to this link >?
http://www.overclockers.co.uk/showproduct.php?prodid=BG-120-OK&groupid=595&catid=683&subcat=
thanks looks like it will be the above PSU and maybe that card

 

[wellabroad]

sorry all i can find inside the comp is the above info in the 1st post, was not sure if this was to do with the mobo MCP78PVM-PM ? PC is about 2/3yrs old now

 

[wellabroad]

Thanks Tamzzy again due to me being a complete thicko regarding the terms what type of card would it allow me to fit ? would it take a GTX 550ti if i upgrade to PSU or do i need to look at the lower end like a 440

 

[wellabroad]

Many thanks Tamzzy, now sorted with a new PSU and GT430 all working fine....even managed to put them in myself...