Can I ask what you were instaling when this happened? As x-ray indicated, I'm also sure it is a virtual memory issue, but the 1.5 - 2x guideline is a bit obsolete, but not harmful. I'd suggest leaving it at windows-controlled. The total size of your hard disk would be helpful too.
I'm thinking that if you're installing something real big, it may require double it's actual size - once for the installation, and again for the unpacked archive of whatever's installing. If it's huge, the installation may still be trying to expand your swapfile beyond what's available. Triply so if it's an Operating System upgrade (since it will also keep your existing files in addition to the new plus the unpacked archive)