My Bold is set up through my company's BES. The company no longer installs the desktop manager as all updates are performed wirelessly.

I'd like to install the desktop manager on my personal laptop for tethering and managing pictures. My question is will I affect my connection with my corporate email if I also connect my Bold to the desktop manager on my personal laptop?

Firstly, you dont need the desktop manager for tethering.
You also dont really need it for managing pictures.
Just plug in the BB, and make sure mass storage mode is enabled.
It will then come up on the PC as two flash drives (one device memory the other media card, if you have one)
and drag and drop like any flash drive.

Make sure you have a tether plan added to your account as well, otherwise you could end up with a really high data bill.

And since you are connected to BES, keep in mind that the company IT Policy on your device might not allow you to do what you want to do.

Is this a company BB or is it your connected to BES?

It's my BB connected to the BES.

I also have an unlimited data plan, although I do understand that they could end up hitting me up for tether plan if they notice a huge increase in data usage.

So if I don't need the desktop manager for tethering, how do I get this to work? Just connect it?

As I said earlier, there could be an IT Policy on it so I would talk to the BES Admin before you do it. Even though it is your device, it is connected to your company data. Many companies frown on such things.

Read: KB05196 - Connect a computer to the Internet using a GPRS, EDGE or UMTS tethered ...

You can use the Desktop Manager installer and just install Device Manager.

Thank you!

you're welcome

Or if you have BT on your laptop, no need for Desktop Manager ;)