When I first purchased my MacBook in 2007 I partitioned my 250GB hard drive to be 190GB Mac and 60 GB Windows (I use XP). I need both platforms since the technology consulting that I do requires me to know both platforms (even though I prefer Mac OS. I decided to purchase Parallels so I wouldn’t have to switch in and out of Boot Camp.  Whether I used Boot Camp or Parallels, my Windows side of Macbook worked well. It was efficient and fast.

As time has gone on though my Windows partition has gotten slower and slower to the point now where it is at a crawl no matter how I boot into it.

I still have 13.9 GB of space on the Windows partition, so space isn’t an issue. I did increase my Macbook’s internal RAM from 2 GB to 4 GB, which I assume should have increased speed rather than slow it down. The slow down has occurred prior to the RAM upgrade.

Any thoughts or ideas would be appreciated.

Right now I’m using Snow Leopard and Parallel’s 5.0 (though it was just as slow with Parallel’s 4.0)

Well, how much RAM have you set aside in Parallels for your Windows virtual machine? When you increased the MacBook’s RAM, did you also increase the amount of RAM used by Parallels? Which version if Windows is it, and how much RAM have you set aside for the VM?

You also may want to do try some of these:

- in the VM configuration, within “Options”,the “Optimization” page, optimize performance for the virtual machine rather than OS X, and optimize power consumption for better performance, if these are not already set.
- a disk defragment within the Windows partition
- if you are ot running from a Boot Camp partition, run Parallels Compressor (within the “Virtual Machine” menu item}
- if you are running a third party security app within Windows, try uninstalling it and running Windows Security Essentials instead, which I understand uses far less system resources than most competitors’ products.
- just do a security scan in general to ensure that you have not picked up some sort of malware

I’m using Windows XP.
My preferences in Parallels is to maximize performance. I tried manually setting the Ram to 2024, since Parallels supposedly only runs using one of the dual processors, not both. The other issue is that it also runs slow just in Boot Camp.
I’ve tried disabling all of Norton Virus and it is still running slow.

I had to reinstall XP once before (many months ago) and that created all havoc in that all of the software that I had installed had to be reinstalled and re-registered, which didn’t work out well. I’d prefer not to have to reinstall XP again.

I tried to optimize the Windows partition from the Windows menu and it said that I didn’t need to optimize.

This is most likely just the standard “Windows is slowing down because of all the cruft in the system” problem. For whatever reason, Windows just starts to grind to a halt. Most people use the “nuke and pave” method of fixing it, i.e. wipe the drive and start over with a fresh install.

2 GB RAM for XP should be plenty. By the way, just because your CPU has two cores, it does not mean that you can only use 2 GB with each core - if it was necessary to provide more RAM to the XP VM, you could certainly do so.

Because you are reluctant to reinstall (and I guess I understand why), it might be a good idea to go through the applications and services that are automatically starting each time XP starts. Quite often you will find things that are unnecessary. On XP, I think that the best way is to run MSCONFIG (you can just click start, type msconfig in run and it will run for you) and go to the “Startup” tab. There will be a number of apps and services listed here, and you can uncheck the ones that you do not need. (One method may be to uncheck something, restart, see if it “breaks” anything, see if XP seems faster, and keep it off, or go back and turn it on if it turns out that it is required.) You can also do a google search for the name of the process and it will almost always come back with links that will describe the process, its importance, and perhaps even the risks and/or benefits of not running it from startup (or if it is known malware, for that matter.)

Anyway, I have XP running in a VM in Parallels 4, limited to 512k RAM, on an early 2007 core 2 duo 2 GHz MacBook (with performance set to favor OS X) and it runs just fine (though I rarely use it - there are only two apps that have important data I occasionally need to check, and I run it most often these days to walk Windows-using friends through troubleshooting.)