Didn't get your query. Could you kindly elaborate with more words please.
If you mean changing the PSU to a higher rated one, there are no side-effects. If its of a good and reliable brand.... pure bliss!
sorry i bought a new graphics card and it needs 550 wattage unfortunately my computer has 250 max wattage i know how to install the card but im a bit confused on how to install a bigger device to suit the card. with that would there be any side effects on the rest of the computers components with a bigger device
No side effects, just buy a new one(make it a good brand like Antec, corsair, or seasonic, dont get a raidmax or anything silly) unplug everything inside the case, unscrew the old unit, pull it out, put the new one in, screw it in, and plug everything else back in.
The key is that, although the wattage output of the new PSU is much higher, the physical dimension will be the same as your old one. So it just fits into the same space. Your system will use as much power as it needs, as long as the PSU can supply it. The PSU cannot push too much power into your system.
One caveat is to make sure the form factors are the same. Is your 250W PSU an ATX PSU, or is it TFX or SFX? The last two are physically smaller. What case do you have, or if it is a pre-built (like a Dell), what model is it?
Otherwise, if it's ATX, the deal hunter315 found is good. I buy Antec or Seasonic PSUs myself, and would consider Corsair, Enermax, or possible XFX. If your PSU is SFX, there is a 300W model from FSP that has received good reviews.
I've seen Thermaltake's NEW PSUs reviewing well, but their old ones are overrated garbage. Avoid any PSU with a little voltage switch on it. At best it is an older, inefficient design. It is probably overrated. And it may be outright crappy, passing too much ripple and noise, or wandering out of spec when loaded.
you can read the PSU reviews from www.hardwaresecrets.com, they are very reliable source of PSU reviews. They test everything and even tell us what kind of Transistors or Integrated Circuit inside the PSU.
The only thing that needs to be consider when you change to a bigger wattage PSU is::: it is expensive especially the good ones :-)