404 Page after trying to install on Joomla 1.5.25

[ren3784]

Every time I try to install VirtueMart 2 on my site, I get a 404 Component Not Found page. I have extracted the two zip files and I have tried both upload installing and directory installing. I tried to install another extension to see if the whole page was the problem but it uploaded and installed fine. I tried to install VirtueMart on another Joomla subdomain that I had to see if the zips were the problem, but it installed fine there too. Does anyone know the reason for a component not found page?