I started using MikTex 2.8 latest version, and encounter strange problem of missing “ifxetex.sty” file. It slower down the tex compiling procedure, because it try to download missing file every time.
A possible solution is:
1- Copy from: C:\Program Files\MikTeX 2.8\tex\generic\ifxetex\ifxetex.sty To: C:\Program Files\MikTeX 2.8\tex\latex\ifxetex\ifxetex.sty
2. In Start Menu -> MikTex 2.8 -> Maintenance (Admin), run “Update (Admin)” and update all pending update-able packages.
3. Start Menu -> MikTex 2.8 -> Maintenance (Admin), run “Settings (Admin)”. and Then from “General” tab, click “Refresh FNDB” and “Update Formats”
Now MikTex shouldn’t download missing file on every run.