Updating Tiger to Snow Leopard after Parallels configuration?

Hi there, First post on this forum.

I am running Tiger on a macpro tower, just downloaded, installed and configured parallels desktop on my mac connected to an external USB hard drive with windows XP on it. That external drive is actually the C drive from my old windows tower plugged in with a universal drive adaptor. It is all working and I am happy with the product. I will probably buy the license next week to upgrade from the trial version of parallels.

So the question is can I upgrade to leopard and snow leopard now from tiger without messing up my paralells desktop configuration? Will I need to reconfigure my parallels installation or anything?

Also I am considering doing the snow leopard upgrade directly from tiger as I heard that works.

Any advice will help.

 

Bump.

Can anyone tell me if my upgrading from Tiger to snow leopard will effect my parallels configuration?