I acquired an HP notebook with Vista pre-installed. The HDD is full and basically contains a Vista partition (which is 95% empty) and another partition containing HP utilities. I tried to decrease the size of the Vista partition using Acronis Disk Director in order to get space to install a dual bootable XP. Nothing happens. DD does not even show the ribbon representing the space occupied by the partition on the disk. I tried to split the partition. I get an Acronis error message telling me the operation is not possible. When I try to copy the partition to a USB disk, Acronis lets me select the Vista partition and the free space on the target disk but the NEXT button remaims grayed out. On the other hand, I can carry out any DD operation with the HP partition. Is this a lock-out by Vista or by HP?

Since your C: is 95% unused as you claim, what you should have done was simply "shrink" that specific volume using Vista's disk management console in an attempt to free up space for a dual boot rather deploying a third party tool for the task. Go try that instead.

I did but I could not obtain a size lower than 66GB although Vista occupies 17. If I can get the size down to 20, I'll be happy. I'm not interested in Vista at all because of its numerous constraints. I'll never use it, just have a look at it. But I need the extra space available on the disk for XP or W2k-sp4. I wonder if this isn't some sort of HP limitation after all.

Problem solved. After a chkdsk on the Vista partition, everything worked fine. Thank you for your help.