QUESTION I upgraded my Windows XP PC to Service Pack 3 (SP3). Every time I boot up the PC it asks for my SP3 disc so it can copy files to the DLL cache. I no longer have this – what should I do? RobLM

HELPROOM ANSWER Dynamic link libraries (DLLs) are batches of code that provide functions to already running programs. These are in place so Windows doesn't need to have many functions recreated in code for each task running, such as network tasks and interaction with the desktop.

You need to run the system file checker to determine which file(s) are corrupt and have them fixed. You need these files for SP3 to work, but there's no need for a disc to hand from which to install them. You could also slipstream the SP3 files into your SP2 disc and create an SP3 installation disc.

There are some great free utilities to do this for you, which add some really good automated features, such as automatic serial number input and feature selection. The process only requires you have an XP installation disc, the new service pack files and a CD burner. I heartily recommend nLite for this task. It's wizard-driven and extremely easy to use.

See also: How to make a Windows XP 'slipdisc'

See also: How to fix everything: the ultimate guide to fixing technology

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