Is it safe to use my computer right now with stock PSU?

[SmoothJK]

Hi guys, I current run the system below. I know it is underpowered by the stock PSU (300W), but I don't get my new one (550W) until Monday. I've only had my new video card and sound card in there for a few weeks, and I certainly don't want them to get damaged. I suspect that my old card (7300GT) stopped working properly because of the PSU...lasted for a good two years, but then again, I didn't play Oblivion back then.

Anyhow, onto the specs:

Gateway GT5252
Processor: AMD X2 4600+
Video: Nvidia Geforce 9600GT
Sound: Creative XtremeGamer
RAM: 4 GB PC4200 533Mhz (3 GB detected)
Other: DVD-ROM, 320 GB 7200 RPM HDD

Everything SEEMS to be working fine so far, but I suspect I'm not getting full performance because of the PSU. And of course, most importantly, I'm worried now that I might overheat some of my new components.

Also, I tried installing PC5300 667MHz RAM, but my computer wouldn't boot properly and it gave me an error message about being outside the range of frequency or something like that. I looked up this part upgrade on a reputable website, so I was surprised it didn't work, and I'm back with my slow PC4200. Could this also be caused by the stock PSU?

Sorry about the questions, I'm a noob here, learning as I go. Any help would be much, much appreciated.

Thanks guys!

 

[Big B]

It very much may be the PSU being inadequate for your needs. It's not to say that other issues don't exist, but upgrading the PSU to a better unit isn't going to hurt.