Hi,
You don't say what your os is or what browser you downloaded 10 with. I've got XP so I don't know about Vista but I think you could try these suggestions anyway.Have you tried to install it from the administrator account? If you can do that and you still can't install it, you could try to reinstall 9 by restoring it from a recent backup from MS Backup or some other backup program. Or you could try to use a recent restore point from before uninstalling 9. After that go to Adobe.com and check their support pages, they have good faqs on installing and upgrading and uninstalling with different oses and different browsers..
Hope this helps.