Vdaxzter: I am running Blood through dosbox (GoG version) on this computer:

HD 6940M/Intel 3000 HD (switchable graphics, although the game runs the same with either)
Windows 7 64-bit
Intel i5 @ 2.3 GHz (goes up to 2.9GHz with Turbo Boost)
8 GB DDR3 RAM

When the game is freshly installed it runs fantastic. However, if I restart my computer it starts to run miserably and I can find no way to fix it. A reinstallation fixes the problem every time. Any idea why the game starts to run horribly after a restart/shut down?

DustyStyx: That does sound strange.
I would try two things

1: When DOSBox is running, you can tell Windows to give it a higher CPU priority. You can do this by pressing alt-ctrl-del and selecting Task Manager. In Task Manager, click on the Processes tab and find the DOSBox entry. Right-click on DOSBox and select Set Priority > High

2: If that doesn't do much, you can also manually tell DOSBox to use more of your CPU. While in game, press CTRL-F12, this will increase the number of CPU cycles it will use. If you find a good number, you can set that in your dosboxGame.conf file found in your Blood installation folder.