I'm trying to troubleshoot a user who is using Outlook 2010 on a brand new system which is a 2.67Ghz i5 system with 4GB RAM, so the hardware performance is a non-issue. We're running Exchange 2010 SP1 at the backend.

The problem is that this particular user has a huge amount of people she is delegate for and looks after a number of calendars for various people. On her previous Outlook 2007 machine, everything was nice and fast, after migrating to 2010 however, it's just slow to use Outlook in general, not massively slow, just a couple of seconds delay switching between folders whereas 2007 was instantaneous. Wouldn't be a big problem for most people but for such a high user who is used to Outlook being able to instantly accept input, she's finding herself wasting a lot of time.


We've tried deleting her OST, recreating her profile, checked all the PSTs were error-free and in 2007 format, ran a compress on them (she has 2 PSTs approx 3GB each).


I've seen various mentions of Outlook 2010 just being "slow" around the net, but I've not been able to find any suggestions as to why this is the case, or ideas to fix it.


The next thing we're contemplating trying is deleting & recreating her exchange account in case there's some odd setting in there somewhere, but who knows what sort of of problems this might cause.        

There's no other apps of any merit running in the background, even when it's "thinking" the CPU load rarely exceeds 30% and that's just Outlook, when idle it's always sub 10%. That said, it looks like Outlook is a singlethreaded app which seems a bit poor. 

Any suggestions would be greatly appreciated, she's getting very frustrated with Outlook, and I'm getting very frustrated with her constant calls about new little niggles she's found.