MSI remember-to's

I am working with a wix installer and i needed to perform a specific task on uninstall.
After coding and compiling the msi, I tried to uninstall the product but I got a nasty error saying that the uninstallation cannot continue. The first thing i thought was 'shit, I cannot uninstall it'.
But here's a solution: MSI copies the original MSI file in the folder:
C:\WINDOWS\Installer
and the filename is in the form of 9c2ebd.msi
You can sort the files by 'Creation Date' if you know when did u install it.

I used then Orca editor to remove the uninstall custom actions which caused the uninstall to be unsucessful.

Also, another useful to know location is
C:\DOCUME~1\[user]\LOCALS~1\Temp
this is the location where the MSI log are written during installation\uninstallation. sort files by 'Creation Date'to see the log.