Performance

[ediko]

Hi everyone.
I have encountered something game breaking. And that is FPS. It's a thread you would expect at sh5 forum .
Alright now is it just me or does every ones FPS crap like mine? In the subs interior itsjumping constantly from 15 to 25 which is not the bggest problem but when I am outside the sub it drops to 12~13 sometimes 9 if I'm in port or a ship burns it drops to 3 fps. I was expecting this game to run flawless considering it's age but well....I forgot how old my pc is.
I have GWX 3.0 installed btw.

Here are my specs.

Intel pentium 4 3.0ghz; 768mb ram; Nvidia geforce fx5200; a broken 320gb drive and a almost working 74gb drive.

I know the pc is crap but still... It is better than recommended specs isn't it?
The only thing I think I could try is reinstalling the OS since it wasn't me who was using the PC for the last year (I had a great notebook which could run SH5 with ease but my sister moved and took it with her.) , maybe it has some viruses. (though AV didn't find anything)
I can only reinstall the Os in a month or so when my friend will get back from vacation since I have to back up some stuff. Any other ideas that could help?