Anybody found a reliable fix for PD 4.0's snail pace? I have now experienced the extremely slow PD 4.0 issue. It seems to coincide with my manual install of Parallels Tools, but MS also released a Windows update the other day. I have tried all of the suggested fixes in this thread and still cannot see an increase in speed. This reminds me of trying to run XP on an old 256 MHz processor machine. Funny thing is that the Mac side is largely unaffected. This upgrade has been the worst experience of any upgrade in my twenty years of computing, but I now have several new friends in India on the Parallels support team. My configuration: MacBook Pro 2.4 GHz Duo 4 Gb of RAM OS 10.5.6 PD 4.0 with Windows XP Pro 2508 Mb RAM dedicated to PD4.0 Adjusting the # of CPU's made no difference nor did allocating more RAM to PD4.0, and when I ran the disk utility there was no affect. Turning off sharing yielded a slight improvement, but what's the point of having 4.0 when 3.0 was faster, and I could file share with more ease. I agree with one of the previous posts that this Official upgrade is more like a beta. I should not have disobeyed my prime rule- "NEVER EVER INSTALL SOFTWARE WITH THE TAG x.0" - wait for x.1 or x.2, unless you like being a beta tester.