If you want to tweak performance of a computer for any reason, regardless whether it's PDF creation or opening email, that's really a Windows function... since you mentioned msconfig.
So, your best bet will be to go to forum for your version of Windows.
I can tell you a few quick hints:
First, if you don't know your Windows Version, Press the Windows key and R on your keyboard to bring up the Run prompt, and type
winver then hit <Enter> or click "OK", and that'll tell you you're Windows version info.
As far as tweaking stuff via msconfig, some can be done that way, some can be done via services, and some by options within individual applications. Just off the top of my head, here are a few:
[ol][li]Quicktime - Anything quicktime[/li]
[li]Real Player[/li]
[li]Nero Back-It-Up (If you're not using it)[/li]
[li]Groove... [If you have Office 2007 with Groove installed)[/li]
[li]Any toolbars and such that are starting up with Windows[/li]
[li]Aside from MsConfig, you can change your performance settings for Windows - Right-Click My Computer, Properties, Advanced, Performance, Appearance Settings - set it to "best performance", hit OK, OK way out... wait for Windows to reconfigure..[/li]
[li]Really, just anything you don't NEED running at the start.[/li]
[li]If you are running Windows XP, and have Windows Search installed (Windows Search 4 is current ver, I think) - it was a separate download under Windows Update - I'd disable it or uninstall it.[/li]
[li]Many autorun backup or disk config programs suck resources from your system pretty bad - at least older versions of Acronis's stuff sometime would put a hurting on decent machines - not always, just under certain cicrumstances..[/li]
[/ol]
Well, that's probably more than you asked for already... Also, depending upon your version of Windows, and your motherboard, you may need more RAM:
Windows XP - at least 1GB, 2GB to 3GB if possible
Windows Vista or 7 - At least 2GB, 3GB if 32 bit, and possible.. if 64 bit, as much as you can stick in there... I'd go with at least 4GB.
For further instructions, give more detail on your hardware/software, and what you are willing and/or able to change, if you really want to tweak things, and post over in the appropriate forum:
for the various Operating Systems... pick the one you have..
Or hardware:
forum602
For instance, it may be that your hard drive is slowing you down. If your PDFs are large, they could be zapping a fair amount of disk usage... if the hard drive is older than 2 or 3 years old, then it's possible, if it's older than 4 or 5 years old, it's practically guaranteed.