If it won't upgrade ... stop trying...
make sure you have the new install saved on your machine...
(personally I'd sack AVG ... get a decent scanner ... such as the equally free ... but unequally superior AVIRA
http://www.free-av.com/
(every review I've read in the last year rate avira far higher than AVG)
either way
disconnect your internet
uninstall avg 7.5
reboot
install the scanner of choice....
reboot
reconnect internet ... enjoy
again personally ...I'd
dump Reg cure ... it doesn't ...
I've never ever ever seen a positive review in any serious mag. they whizz and bang ... but it's impossible that any app could know every possible combination for every possible version of every possible prog in the world ....(just thinking about it gives me a headache)
the other two are OK ... shouldn't need re-installing