To my understanding, Windows Installer 4.5 comes bundled inside Vista SP2. That's why if you're looking at / trying to download MS Installer 4.5 from MS KB 94288 Windows Installer 4.5 is available it only lists Vista SP1.
Unfortunately, that still doesn't explain your problem. Are you certain all Windows updates have been applied?
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And (above) is why it won't install from the MS download on top of SP2 since it should already be there
So far, you haven't told us what operating system you use, what you're trying to install and 'where' you are trying to out the installer that it gives you the message 'not enough server information'.
IT would also help t know which 'server' is being referred to.
If misery loves company, seems there are many recent complaints of MSI 4.5 failing in Vista 64bit (you can look through the "Community Content" posts here)
Yet another reason i, personally, don't want to use a 64bit version of Windows