I have one machine, a Dell GX520 that didn’t want to fully boot the UBCD4WIN from CD, or from USB for that matter.
From http://ubcd4win.com/forum/index.php?showtopic=9899
I’d probably first suggest that you download the latest MassStorage DriverPack from http://driverpacks.net …
Place the 7z file in the [UBCD4Win]\plugin\DriverPacks.net\BASE\DriverPacks folder.. remove the older pack.. then rebuild the driver packs from the Plugins area
If you still have issues.. go into the Bios settings and see if they have a option similar to a “Legacy” setting or not and try changing it to that.
After you download and replace the driver pack then you go into the Builder-> Plugins … highlight the one that is obviously labed… “# DriverPacks.net – BASE – Press <CONFIG> to enable or reset DriverPacks plugins” and as it states, press the Config button which then will cause it to rebuild the drivers which you can watch the progress of.