Winfixer has completely shut down my computer?

try booting in safe mode hit f 8 repeatedly as win loads.install hijackthis scan and post.results at hijackthis site.they will help you for free.if that fails.I would reinstall win.get ubcd4 and make bootable xp pe disk, you will need xp cd to make a pe disk.with that you can backup your data.or maybe find post on ubcd4 site to fix with pe disk