Question : Vista Home Premium and MS Works 4.0 created an unstable environment on a Dell XPS Desktop?

I directed a client to buy a Dell XPS desktop with Vista and Office 2007, she wanted a long term solution.  She had been using Windows 98 and Works 4.0 and now wanted DSL Internet service and email.  She wasnt happy with Word.  I did a compatibility check and Vista let me load Works 4.0.  Now I think its corrupted Vista, the box is unstable and I cant seem to get the right help to uninstall it and repair Vista.  My client will not let go of Works (she uses it more efficiently than anyone Ive met).  Shes regretting this entire move and I dont blame her.  If I had hind sight I would have approached this problem differently.  I have Works 8.0  ready to install.  My question is what are my options to stabilize the PC and make her feel comfortable with her new tools?
1. Do a system restore back to factory settings and reload ISP software, HP 7680 All in one software (~1.5hrs) and load 8.0 (it looks like her 4.0 documents will convert to this version (I didnt know this a few weeks ago)?
2. Uninstall Works 4.0, do a registry check of Vista and install Works 8.0?
3. Uninstall Vista and load XP?  Will this void the warranty?
Other ideas?  She wants to use Works.  I hope Works 8.0 does the trick. She probably will not share the Works documents, but will probably receive Office documents.

Answer : Vista Home Premium and MS Works 4.0 created an unstable environment on a Dell XPS Desktop?

Getting Works 4.0 uninstalled is the first step. What exactly happens when you try to uninstall it? As I recall, Works has its own uninstaller.

Are you familiar with the Compatibility Wizard in Vista? http://support.microsoft.com/kb/555917