Which version of Windows are you using?
Is that version "up to date"? Do you do all the regular Microsoft updates for the OS? Some say don't, I say do. It's religion though, so you gotta make and take a stand on this and go from there. Some hardware drivers are only compatible with some versions of Windows, so you need to check with the manufacturers if things don't work easily the first time or two.
I just went through a similar situation with another MIDI device, a DigiTech GNX-3, for my buddy. We installed its X-Edit editor on his main PC, the one the whole family uses for email, surfing, games, media, etc - after three hours, several uninstalls and reinstalls and reboots later, and still sitting there dumbfounded, we decided to try it on his notebook - it worked perfect the first time. So if you can try the installation on another machine, it may fly easily, then look for the differences in the two machines to narrow down the problem.
Things like
scanners or printer/scanners (multi-function), webcams, and other real-time device drivers can play havoc with MIDI devices because they do what's called polling - they repeatedly interrupt whatever the computer is doing to check if they have anything to do - including your midi and audio apps. Disable such things in a custom configuration, if you want to make music without annoying disruptions and sometimes even crashes.
Do you use the machine for "everything"? Is it you only PC?
If it's you main PC and you use it for everything, I would recommend getting a second PC for music stuff only. Keep it a lean and mean music machine and do all your media, graphics, photo work, PRINTING, surfing and gaming on the "other" box.
In my case, I have one 3.2 GHz CPU, 2GB DDR (hand built) DAW machine, set up just for multi-track recording. It runs Sonar and a select few other apps, like MIDI-Ox, to keep it focused on recoding well. All its settings are tweaked to
optimize multi-track recording. It mates with a Behringer DDX-3216 digital mixer via a dual ADAT interface from Steinberg. I spent a little money on this part of the studio, but much less than a lot of others have. Altogether it's about $1500 for the 16-channel DAW.
I have a second $100 OLD PII Dell notebook running Win-Me as my MIDI workstation, running the editors for my MIDI gear, Bome's MIDI Translator, Soundplant (sample player), and PAS's MIDI Program Change Manager to sequence everything MIDI for my guitar thru all their MIDI settings in live use.
I have another old used touchscreen PC running Win-2K that I use as a MIDI controller for my keyboard station in the studio. That runs azMIDI to control the multi keyboard setup, to sequence everything MIDI for my keyboards thru all their MIDI settings during performance.
For controlling MIDI, there are tons of old cheap PCs (and Macs) out there waiting at a garage sale, Craigslist or second hand store
near you. Keeping them tasked to one or a few things can greatly reduce configuration problems by minimizing driver and other configuration conflicts.
Just some ways I use my PCs, FYI. Good luck.
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