driving Disney Paris to Versailles in July--OK or take the train?

Drive time is one hour without traffic delays, per www.viamichelin.com. This is the arrival/parking note from Rick's France book, which sounds pretty easy:

By Car: Get on the périphérique freeway that circles Paris, and take the toll-free A-13 autoroute toward Rouen. Exit at Versailles, follow signs to Versailles Château, and avoid the hectic Garden lots by parking in the big pay lot at the foot of the Château on Place d’Armes (€8/2 hours, €16/4 hours, €24/8 hours).

I know it would take a bit longer , but to me it would be so much less hassle to get on the train and not have to worry about any traffic and parking . It's only a 10 minute walk from the station to the palace

You can easily drive this route especially on a Sunday. Tuesday...not as much fun and will most likely take twice as long but still doable. Just make sure you have a good navigator in the passenger seat to help! Make a wrong turn and it's really difficult to get back on the right route.
I would be of a different opinion than Rick on parking...we always prefer to park in the grounds of the palace when we visit. You can park directly at both the Petite and Grand Trianons, the Petite Hameau, and in the trees right next to the Grand Canal. You pay a small entrance fee at one of the two gates to the grounds + an additional amount based on the amount of time you stay in each lot. We have always found it to be cheaper and much more pleasant than the giant lot at the front - there are no parking garages at Versailles that I am aware of. It's also a much nicer approach coming to the palace through the gardens in the back (IMHO) than going through the front of the palace and the hoards of people who enter there.

If you continue to wish to drive that route, please, please, please read everything you can about driving on the périphérique. It is different than any other road I have ever driven on, and I have driven a lot of strange roads in my time.

It is very narrow, nowhere near straight, the ramps are tiny (Cross Bronx Expressway tiny, maybe tinier), traffic joining has the right of way (LA PRIORITÉ À DROITE is in effect on the périphérique) and causes all sorts of interesting results. I find the signage on the périphérique confusing and twice have made the wrong turn. It isn't much fun getting back on.

I don't want to dissuade you (although I would take the RER) but I want you to know what you are getting into. Laura's comments are good but it sounds like she has never actually been on the périphérique.

If you like to use the car it is to my opinion better to follow the A86 freeway route, being the larger circular freeway around Paris. Coming from Disneyland Paris on the A4 follow direction Créteil - Paris and avoid taking the first exit to A86 (little red sign on top of the big ones) with direction A1. You need to go to the next exit to A86 about 3km further and there follow Bordeaux-Nantes-Lyon and if I am not wrong Versailles is alraidy indicated or at least soon.

This route is a bit more convenient than the Périphérique and even a bit shorter. Think about an hour driving, plus some time for looking for a parking spot. But be aware of various speedlimits, some places with 70 km/h if I remember well. Driving back follow direction A4 Metz-Nancy-Marne la Vallée to exit Parcs Disney. Be also aware that many Parisiens after a weekend trip come back home on Sunday later in the day and expect roads will be busy.

If you like to take the RER but have to drive to a station there is a large free parking lot near Val d’Europe shopping mall, the railway station is a short walk away.

Wil is right about taking the other route. But be careful because your GPS could insist on taking you up to Paris and putting you on the peripherique instead of the route that goes south near Orly. I speak from experience. It's fairly heavy, crowded suburban driving with a lot of on and off ramps, merging autoroutes, like around LA or DC.

The Sunday evening drive back should be hellish, on the other hand, even worse than Tuesday. Everyone who went away for the weekend is heading back toward Paris Sunday evening. It's like the Jersey turnpike on a holiday weekend.

thanks to all--we will take the train or hire a private transfer--that was just the reality check that I was looking for. We will use the car to go for the day to Vaux le Viconte near Melun (sp?) and to Reims and then to Colmar, where we will drop our car. I assume driving to those should be OK?

Those should be ok, but there are no guarantees. I see you're from DC, so you understand.

Taking the train is fine but just note that you will have to make two connections to transfer from the RER A line to RER C. You do not have to drive on the peripherique (which I have driven on and found much less annoying than the Cross Bronx) to get from Disney to Versailles. Wil had given excellent driving directions that take you nowhere near any area where driving is difficult. Laura has basically given you directions from Paris to Versailles.