Having problems with using shift alt command when using the square tool

Question

having problems with using shift alt command when using the square tool

Answer 1

Marco,
If no good reason, such as the one suggested by Silkrooster, is present, you may try the list, hoping for one of the easy ones at the top.
The following is a general list of things you may try when the issue is not in a specific file, and when it is not caused by issues with opening a file from external media. You may have tried/done some of them already; 1) and 2) are the easy ones for temporary strangenesses, and 3) and 4) are specifically aimed at possibly corrupt preferences); 5) is a list in itself, and 6) is the last resort.
If possible/applicable, you should save current artwork first, of course.
1) Close down Illy and open again;
2) Restart the computer (you may do that up to at least 5 times);
3) Close down Illy and press Ctrl+Alt+Shift/Cmd+Option+Shift during startup (easy but irreversible);
4) Move the folder (follow the link with that name) with Illy closed (more tedious but also more thorough and reversible), for CS3 - CC you may find the folder here:
https://helpx.adobe.com/illustrator/kb/preference-file-location-illustrator.html
5) Look through and try out the relevant among the Other options (follow the link with that name, Item 7) is a list of usual suspects among other applications that may disturb and confuse Illy, Item 15) applies to CC, CS6, and maybe CS5);
Even more seriously, you may:
6) Uninstall (ticking the box to delete the preferences), run the Cleaner Tool (if you have CS3/CS4/CS5/CS6/CC), and reinstall.
http://www.adobe.com/support/contact/cscleanertool.html