An alternative to PageDefrag for Windows 7 does exist! This free, open source program that will defragment the system page file in Windows 7 after boot up is called UltraDefrag, and is available as a download at SourceForge.net. Ultra Defragmenter comes in editions that work with Windows XP, 2000, Vista, and Windows 7, and it comes in 32-bit, 64-bit and Itanium Editions.
Boot time defragmentation mode is enabled with a click or two, after which it will defragment any system file at re-boot, including page file, registry hives, hiberfil.sys file, etc. It does not have the one-time defrag option that Page Defrag (pagedfrg.exe) has, so if the PC owner wants it to run only once, he/she has to remember to uncheck the boot time defragmenting option (after reboot and page file defragmenting are completed). I have personally used this utility on a couple of Windows 7 installations and have been pleased with the results and the absence of any problems. I use this only for boot time defragmenting, and let the native Windows defragmenter handle the rest of the files, and the two seem very compatible when used in this way.