I have seen some of these issues regarding Microgaming casinos sometimes spinning slow. I know of a couple of things that have helped me, I am running a copy of Windows Vista right now....but, its a good recipe.
First tip: Delete your browsing history. Be sure that you know your login details before hand. Go to your browser's tools, and delete ALL history, temporary internet files, cookies, history...etc. I just usually check the box that deletes ALL of my passwords, forms, cookies...also make sure that your casino software is not running.
Second tip: Refresh often. Most Microsoft Windows Apps usually use F5. You can do this just before you spin. My wife says she likes it better when you "minimize" the window, then "maximize" the window again, making it appear and reappear. She claims that you only have to do this once, each game.
I just prefer to go ahead and delete my browsing history, cookies, from your internet browser Tools menu. Next, start the casino software. When I showed her this, it worked for the most part, only a couple games were slow, just for a couple spins, but she showed me to just minimize it before the first spin and it straightened itself out.
Third tip: This isn't for the faint of heart. I have my Temporary Internet Folder on a seperate partition on my hard drive. I created a seperate E: partition on my hard drive, and store my Temporary Internet Folder on this drive only. This partition is 3 Gig and its overkill.
Click on System Properties. I right clicked on My Computer and Selected System Properties, and then selected Advanced. I clicked on "Performace" and selected "settings". Next, click on "advanced" then select virtual memory "change" Click on your active hard drive, (probably C:) and click on "custom size" Don't over do it. Find the range that closely matches how much memory you have in your computer.
Since I have 2 Gig of memory on my computer I will want to have about 2500MB to 3500MB of virtual memory allocated. If you have 1 gig of memory, go with 1200MB to 1800MB of memory allocated. Try to store this paging file on your newly created partition (mine is E:) on your hard drive. I play at a few Microgaming, like Villento, Rich Reels
, Golden Tiger
, Casino Classic, 777
Dragon and it works for them.