It is a sad truth that running Outlook 2007 on Vista can cause even the fastest computer to slow down to a painful crawl. When using Outlook with an exchange server the bottleneck is the OST file. The amount of disk activity generated by outlook is significant. The problem is, Outlook itself is not the only offender! In Vista the indexing service also molests your OST file repeatedly while it sorts and indexes all the email, spam, contacts, calender items, and everything else that Outlook uses. Add to that that Microsoft Communicator’s Outlook integration causes constant accesses to your OST file and you have an absurdly large amount of disk activity that never stops, even when you aren’t doing anything!
My solution: Put the OST file on a RAM drive! Since the OST is causing a disk bottleneck, we will just get it off the disk.
Step 1: I am using 1.2GB of space on the exchange server. In addition to consuming large amounts of disk space, it is causing the indexes mantained by Vista to grow ever larger and generate more disk activity. So task #1 is to configure autoarchiving and then run it to reduce the size of your mailbox until it will fit comfortably into memory. My target was 128-256MB. That doesn’t sound like much relative to my 1.2GB, but it represents nearly all of the mail I access on a regular basis. Compact your OST file when you are done to verify its size.
Step 2: I need a RAM drive. At work I run Vista x64, which adds a further level of difficulty since I need a 64-bit RAM drive. I found one that works nicely in this thread at PlanetAMD64. There are others, but this one is free and it works. In Vista x64 it creates an error on boot because the driver is unsigned but you can boot up anyway by pressing F8. In Vista x86 you can disable driver integrity checks through the boot loader, but not in Vista x64 RTM. There is a way to sign your own driver so this doesn’t happen; anyone have fast and painless instructions for this?
After you install it and reboot you will need to format it and save blank volume image. The readme describes how to do this. You can format it with the file system of choice. I wanted something that would not waste too much space and be fairly fast so I used exFAT with a 1MB cluster size. If that is what you want, use this to format your drive:
format r: /fs:exFAT /V:RamDrive /A:1M
If you are using Vista x86, exFAT support seems to be absent. So if that is the case or you are just afraid of exFAT, use your file system of choice. The bigger your cluster size, the better, but be sure you can utilize most of your drive. Your usable disk space will be in multiples of your cluster size and you need room for your FAT. (So on a 256MB RAMdisk if you have a cluster size of 16MB that is 256/16=16 clusters. Except that a little bit is used for the FAT so that is only 15 clusters resulting in a usable disk space of only 16*15=240MB!)
When you are done, save the image to the registry using the command line in the readme file.
Step 3: Move your OST file to your RAM drive. Right click on the Outlook icon and open properties, click on E-mail Accounts, double click on Microsoft Exchange on the email tab. Click on More Settings on the wizard, go to the Advanced tab. Uncheck “Used Cached Exchange Mode” and click Apply. Click Offline Folder File Settings. If the file name is greyed out you either have Outlook open or another application open that uses the OST file open. Put in r:\outlook.ost as your file and click OK. Re-enable Cached Exchange Mode and click OK and then get out of your dialogs. Start up Outlook. It will download a fresh copy of your mailbox and Vista will immediately begin indexing the new OST file.
Step 4: If you made it this far, Outlook is running fast and the rest if your computer is running almost as fast as if you didn’t have Outlook open at all. The only thing left to do is to make sure the OST file gets saved when you shut down and copied back to the RAMdisk when you start up. If you used a RAMdisk other than the one I linked to, this might be done for you. However, it is an easy enough task to do this yourself. Create two .cmd files in the folder you are running the ramdisk4g out of called startup.cmd and shutdown.cmd. Create the two files with the following text:
startup.cmd: copy /y “C:\Users\stephenn\AppData\Local\Microsoft\Outlook\outlook.ost” r:\outlook.ost
shutdown.cmd: if exist r:\outlook.ost copy /y r:\outlook.ost “%userprofile%\AppData\Local\Microsoft\Outlook\outlook.ost”
Then, open up the group policy editor (run “gpedit.msc” to get there quickly) and navigate to “Computer Configuration\Windows Settings\Scripts(Startup/Shutdown)”. I trust you can figure out how to add the two scripts to your startup/shutdown sequence.
The End! If you loose or corrupt your OST file it won’t matter. Just recreate it. It is just a copy of the stuff on the server. If you attempted to follow my instructions using a PST file, try not to wipe out your inbox forever. 
Note: “Disk activity” to r:\outlook.ost doesn’t show in performance monitor anymore. Reads and writes to your RAM disk are completely absent. Now you can search and destroy new bottlenecks.
