Missing Driver Parallels 5 change over to Lion

I've never had any problem with parallels but after switching to Lion I can no longer log in. When trying to, it says "Unable to load the Parallels Driver Please Restart your Mac and try again." Any idea how I can fix this?

 

AFAIK Parallels 5 wasn't updated to have Lion compatibility, only the latest versions of PDM 6 and 7 are compatible with OS X Lion from what I know.

It's generally advised to check for your software compatibility before upgrading your Operating System, specially a software like Parallels.
You have 2 options, either go back to Snow Leopard or upgrade to PDM 7.

 

Is there anyway for me to switch my version of Windows 7 to just boot camp?

 

WARNING: This won't be simple.. At all.

Get the Parallels 7 trial (you'll have 30 days). Then you can try this procedure (written for XP, shouldn't be too different): http://forum.parallels.com/showthread.php?t=6433

 

What if I don't have the Windows install disk, I used the online download version

 

Burn the .iso to a DVD.
The procedure doesn't state any alternative to not having a Windows disc.

And frankly from my experience there's no way to pull this off without the Windows disc. You already asking for something difficult, you were given a proven answer, if you can't have access to the necessary tools, forget about it.

Probably your best bet is to convert the Parallels disk image to a VirtualBox one, but that requires installing the Parallels trial first to remove the Parallels tools and prepare it to be exported. I'm not sure if VirtualBox can read Parallels file directly but it can read VMWare's and VMWare (they have a trial too) can read Parallels, so you might need an extra loop there.

None of this is simple, but it is doable. I'm not going to give you step by step instructions, for two reasons: They would be lengthy and I can't think of every possible way things might go wrong and what has changed in these programs, there will be some trial and error.