Start by providing some information like
- your operating system;
- your current Adobe Reader version;
- the update you are trying to install;
- any other relevant information that we do not have.
I'm running windows 7 x64 home premium on a Toshiba laptop with 4gb of ram. My correct version of reader is 9.3.0. I'm not sure what the version the update is that the system keeps trying to install.
Try to install the available updates exlicitly; download
- http://ardownload.adobe.com/pub/adobe/reader/win/9.x/9.3.1/misc/AdbeRdrUpd931_all_incr.msp (save to disk);
- http://ardownload.adobe.com/pub/adobe/reader/win/9.x/9.3.2/misc/AdbeRdrUpd932_all_incr.msp (save to disk);
Close all browser windows, as well as Adobe Reader, then run the updates in sequence.
I still get the same errors, first 2503 and then 2502 after I clear that one when I try to install the updates you sent me.