Miss XP and really miss Windows 7.
There is a solution to that. You stay with Windows 7 and use other methods to keep it safe and current. [eg 0patch].
The issue is typically not with memory-intense GUI changes... that's a thing of the past with both Modern OS memory management and modern systems having oodles of ram.
The issue arises when 2 competing programs are trying to modify [skin] the same GUI component/s.
As brad_sams suggests try all the Windowblinds skins and its options without running Openshell. You will find everything will function as it should [other than newer OS changes/updates thanks to MS that may have not yet been accommodated].
Lately Windows 7 has been left behind by Microsoft to the point I really needed to be using Windows 10 [at least] but simply loaded that into a Virtual Machine instead.
I let Win 10 play with 4 cores and 8 gig of ram, Win 7 gets the full 16 cores and 64 gig ...