i've heard one too many complaints about the speed of virtual pc with windows running on mac. so i decided to help those of you out that want your VPC to run a little faster. 1. memory. for your machine to run quicker, it will need a significant amount of *FREE* memory. even if you know this already, please read all of it. for windows 2000, you will need at least 192 MB for VPC for it to run at a decent speed. for windows xp, 256. here's the trick though, too many people think "oh, i have 512 MB, thats enough to give 256MB to VPC". wrong! you will notice that even if you have no programs running besides VPC, 256MB for VPC on a 512MB mac will be painfully slow. why? because there isn't enough FREE memory, and the system has to balance the memory which results in a slowdown. to find out how much you have free, close every program, including VPC, go to Applications/Utilities/Activity Monitor, go to the memory tab, and see how much you have free. if its less than 256, you can't use 256. try stopping services to free up more. i have 768MB in my powerbook g4 and its enough to use VPC with 256MB ram. 2. video memory. the default VPC setting is 4 MB allocated. but, if you have a 64 MB or greater video card, go into the settings for the computer, choose the memory option, and bump it up to 16MB. this speeds it up greatly. 3. disable visual effects. find the performance options (in windows xp, under control panel) and choose "best for performance" and disable all the visual goodies. you don't need them. 4. in windows xp, use the "Classic" theme. this takes less time to draw on the screen, and speeds it up. instead of using the blue/green/red XP theme, the classic theme doesnt have any bitmaps covering up the window, so it runs quicker. 5. disable desktop images. i know they're cool, but they slow down your computer. any time VPC needs to show an image, it's going to slow down. 6. stop unneeded windows services. there are a bunch of needless windows services you can stop. like print spooler, if you dont print. but be careful. 7. consider disabling USB and networking. if you don't use them, definitely disable them. networking especially slows down VPC. I just use VPC for visual studio development, so i dont need a network connection. and this helps prevent viruses bigtime. 8. check for spyware. should be obvious. 9. remove unneeded items from starting up. like MSN messenger if you don't use it. the less programs you have running in the background, the faster it will be. 10. use as low of a resolution you can handle. if you don't need your VPC running at 1600x1200, don't use it that high. also, consider using 16-bit color instead. it looks just as good most of the time, and helps speed up the system. 11. use the FAT file system. not only does this allow you to mount the drive with Finder, but NTFS is far slower than FAT for VPC. 12. don't run other mac programs with VPC unless you need to. 13. keep the windows hard drive defragmented. 14. THIS IS A BIG ONE. if you do use networking/internet with VPC, USE INTERNET EXPLORER INSTEAD OF FIREFOX. i know, i love firefox far more than IE, and bring on the flamers. but firefox is painfully slow in VPC (unless you happen to be running it on a G5 i guess, but for the rest of the world on G4's, its slow) and IE is very fast. but make sure you lock down IE to prevent spyware and unwanted activeX controls. and basically, disable anything you dont use, keep the system maintained, and do all the above. and you'll have a rather usable virtual PC. i do visual studio.net 2003 development on windows XP in one, and it runs great, but slow as molasses if the above are enabled. but then again, doing development work, you dont need desktop images for example. hope this helps.