Access denied while creating partition

I'm hoping somebody out there can help me -- or, more accurately, help me help my mom! With the death of XP, both I and my mom went out and got ourselves brand new HP desktops, running Win7 Pro 64-bit. They came with the OS installed and ready-to-go (other than a bunch of Windows updates), but we both wanted our hard drives partitioned -- one drive for system stuff and programs, and another for our data/files. I did this on my computer first (which has about twice the disk space, RAM, etc. as my mom's has --although her computer is still very good, too), following the instructions that I found here... How to Partition Your Hard Drive in Windows 7: 12 Steps - wikiHow Everything went smoothly, no problems whatsoever, easy as anything -- and so I thought I'd walk my mom through the process over the phone, too (after having her thoroughly and completely defrag her hard drive). Well, everything seemed to be going smoothly, I suggested that she split her 500 gig hard drive into 80 gigs for her system/program files, and the keep the rest for her data, and she managed to get the appropriate numbers put in the correct spot (as per step #4 at the above link), and then she pressed the "shrink" button... and then something went horribly wrong. An error message popped up from "virtual disk manager", saying that "access is denied". Strangely, now when she looks at the info shown in the Disk Management utility, up at the top where the drives are listed there (black text on a white background), it shows that her C: drive is indeed now ~80 gigs* in size. However, down below that -- in the gray half where the "squares" are showing the drives, her C: drive still shows up as being it's original size of ~500 gigs*, and there's no unallocated partition showing up at all. (* Please note that I'm simplifying the numbers here, and not taking into account two partitions, D: and E:, that HP creates for recovery utilities) I've searched all around the 'net and can't seem to find any solution to this problem, let alone any discussion board where anyone else has encountered something like this -- perhaps this has come up here before, but I can't seem to find it. Can anyone help? I don't know what to do. Now it would appear that her C: drive has indeed shrunk to ~80 gigs, but we can't seem to "see" the unallocated space that should be there for us to create a D: drive from. Any suggestions would be most helpful, and I'm extremely grateful (for my mom's sake) if anyone can help. Thanks so much in advance! :)

PS. Sorry for that all coming out in one big paragraph! I did have my query all nicely formatted into separate, easily-readable paragraphs, but somehow that all got lost as soon as I posted it it. I have no idea why. Sorry about that. :/

AddRAM said:

80 GB is too small, keep it around 150 GBs.

I would get over there and handle it personally.

Post a shot of disk management for us before you proceed.

Really? 80 gigs is too small? After my mom did all the Windows updates, I asked had her check how much disk space she was using and she said it was about ~35 gigs or something -- I figured that 80 would be plenty. Indeed, for myself I set my C: drive to 100 gigs, and even after install a LOT of software -- including the full Adobe Design Suite (Photoshop, Illustrator, Indesign, Acrobat, etc.) and a bunch of video editing software, etc. -- I'm only up to about 64 gigs being used. Just how much free space does one need, just to run the OS and programs? As for a screenshot, and going over there myself, it's a bit of a pain to get out to where my mom is (she lives on the outskirts of town and I don't have a car), and I don't know what info a screenshot would give you other than what I've already described in my original post. If there's anything that you can suggest that I could ask my mom to look for -- or something to "do" that might fix this error -- that would be easy enough to pass along and report back on. Thanks very much for your reply, of course! :)

I have a screenshot ready to post here of what my mom sees in her Computer Management window, but this is weird... not only do I seem to keep losing my formatting, with separate paragraphs, whenever I post here, with everything coming out as just one, big, long paragraph, but I can't seem to click on any of the formatting buttons either -- no bold, no italics, and clicking on the paperclip icon to attach my screenshot doesn't work either. I've tried to do this now in both IE and Firefox -- same thing happens in both, none of those buttons work. Any ideas???

AddRAM said:

I`m just saying it`s a 500 GB drive, why not just make C bigger ?

Better to keep it large from the get go, 80 GBs can get filled fast

Oh, basically for two reasons... For one, my mom's using C: for system and program files only, and putting all her data on a separate partition (at least, if I/we can manage to get that partition made, of course!), and if she's not going to be using all that space on C:, then why waste it? It would just end up sitting there unused. Which brings me to the second reason: my mom has a LOT of music, etc. that she likes to keep on her computer, so that'll invariably end up eating up a lot of disk space, so it's nice to have that other partition as big as possible. On her old computer, she was constantly having to back up to external drives, which is a pain, of course. (PS. I have no doubt that my reply here will end up coming out in one big, long paragraph again -- even though I'm typing it in here in separate, smaller paragraphs. And still none of the buttons/icons work for me, I can't italicize or bold, let alone add the screenshot I have that I wanted to load up.)

Turns out that in the process of partitioning the hard drive, something got "damaged". I had my mom call HP to try to resolve the issue (it's a brand new HP computer, still under warranty, of course) and they hooked up to her computer through the 'net and checked it out, and she has to re-install Windows. So thanks very much for your help, nevertheless! I guess there wouldn't have been anything you could have done anyway -- it's apparently an issue that's much bigger than just some kind of "fix" that I (or someone) could have just poked around and resolved. I'm sure we'll get it resolved now with HP's help -- and, if not, well, we'll have to get them to replace it, if it's "broke".