but I do not know where to ask for assistance

one often overlooked place is the source of the software :)

since its an MSI installer , I would also look for help at microsoft. The possibilities seem to be

• more information might be available in event viewer (eventvwr.EXE)
• bad hardware/ram module (run memtest...)
• missing service not running
• insufficient permission (allow to interact with desktop)
• bug is resolved by some hotfix/windows update
• there is interfering malware/spyware (run hijackthis/spybot/adaware....)

so to manually uninstall

• find and delete your strawberry perl directory ( rm -rf strawberry )

  This should be enough to allow for reinstall

• you might need to fire up add/remove programs (and some cleanup tool whose name i can't recall) to remove strawberry perl program entry
• fire up regedit and search for and remove references to strawberry (path/pathext/assoc ..)
• maybe cleanout "%userprofile%\local settings\application data\perl..."

Thats it :)